CN220828846U - Drainage integrated boiler and drainage system for carbon dioxide trapping - Google Patents

Abstract

The application relates to a hydrophobic integrated boiler for carbon dioxide capture, comprising: the integrated water draining boiler comprises a boiler body and a water draining tank body, wherein the integrated water draining boiler comprises a liquid inlet and a liquid outlet which are respectively positioned on a first sealing head and a second sealing head, and also comprises a steam inlet and a liquid outlet which are positioned on the side wall of a shell; the boiler body provides a place for heat exchange between the amine solution and the water vapor; the drain tank is arranged close to the second end socket side and positioned below the boiler body, and is configured to store liquefied water vapor. The application also discloses a drainage system which comprises the drainage integrated boiler, a drainage pump and a valve; the drain pump is configured to pump condensed water vapor to a plant condensed water system or unit drain tank. The application can recover the hydrophobic water in large-scale carbon dioxide trapping engineering, simultaneously recover energy and working medium, save a large amount of energy sources and create conditions for popularization and application of the carbon dioxide trapping engineering (CCUS).

Description

Drainage integrated boiler and drainage system for carbon dioxide trapping

Technical Field

The application relates to the technical field of carbon dioxide trapping, in particular to a hydrophobic integrated boiler for carbon dioxide trapping, and also relates to a hydrophobic system comprising the hydrophobic integrated boiler.

Background

The resource endowment of China determines that the high-efficiency coal-fired generator set still occupies an important role in the power system of China in the middle and long term, and the important direction of the current research is to reduce the energy consumption loss of the carbon dioxide capturing process and improve the safety and reliability of equipment.

According to the flue gas characteristics of the coal-fired power plant, an alcohol amine absorption method is the first choice of the flue gas carbon dioxide capturing technology of the coal-fired power plant. The technical principle is as follows: the flue gas from the boiler is firstly subjected to purification measures such as denitration, dust removal, desulfurization, water washing and the like, and parameters such as temperature, pressure and the like of the flue gas are adjusted so as to meet the requirements of a carbon dioxide absorption tower. The purified flue gas enters a carbon dioxide absorption device, carbon dioxide in the flue gas and lean amine solution react and are removed, and flue gas (the main components of the flue gas are nitrogen and water vapor) without (or with a small amount of) carbon dioxide is discharged through a chimney. The rich amine solution rich in CO2 is desorbed in a desorption tower, the desorption process is heated by a boiler to release high-purity CO2, the regeneration of the absorbent is realized, and the lean amine solution is changed into cyclic utilization. After high-purity CO2 is captured, pressurizing, liquefying and transporting, sealing or utilizing, wherein the system flow is shown in figure 1, and the system comprises an induced draft fan (1) and a rich liquid pump (2); a lean liquid pump (3); a lean rich liquid exchanger (4); a solution boiling vessel (5); a regenerator (6); a lean liquid cooler (7) and an absorption tower (8).

The energy consumption of the carbon dioxide trapping process mainly occurs in the desorption process of the rich amine solution, a large amount of steam is required to be input into a boiler to heat the rich amine solution, carbon dioxide adsorbed by the amine solution is released, and the carbon dioxide is separated through subsequent processes such as drying, purifying, liquefying and the like. The carbon dioxide capture desorption process requires a large amount of steam, generally about 1.2-1.5t steam/t CO2. When the trapping scale is smaller, the steam is changed into condensed water with the temperature of about 100 ℃ after being released by the boiler, and the condensed water can be sent into a unit drainage tank or a pit and the like for working medium recovery; when large-scale carbon dioxide trapping is adopted, for example, the carbon dioxide trapping amount of 50-100t/h per hour is calculated according to the carbon dioxide trapping amount of 1.2 steam/t CO2 with higher efficiency, the steam/water drainage amount reaches 60-120t/h, and a large amount of condensed water with higher temperature (100 ℃) can cause energy loss and visual (steam) pollution if directly discharged, and a large amount of cooling water is also required to be cooled to be sent to a pit or a unit drainage tank.

In the typical current process route, the common amine solution is limited by the reaction temperature, the reaction temperature is 105-110 ℃, and the required steam is within 150 ℃, so that the required steam is low-quality (about 0.3MPa, 140 ℃) saturated steam; the heat required during desorption is about 2.2-2.8GJ/t CO2 (about 1.2-1.5t steam/t CO2 converted to steam). Therefore, a large amount of steam is needed in the reaction process of the large-scale carbon dioxide capturing process, for example, the project is put into operation, the carbon dioxide capturing amount is about 12-15 ten thousand tons/year, 18-24t of steam is needed per hour, condensation water at about 100 ℃ is generated after the steam is condensed, and the common measure is that the condensation water is simply recycled as working medium, and heat is not recycled. The quality of the condensed water is equivalent to that of desalted water, but in the recovery process, the impurity content in the water is increased due to the mixing with industrial water, and the mixed water quality is basically equivalent to that of industrial water, and the water can be changed into desalted water again after further purification and treatment.

In the thermodynamic system of the thermal power plant, the low-pressure heater also adopts a mode of exchanging heat between steam and condensed water, a water storage tank is arranged at the lower part of the low-pressure heater, a drainage pump is arranged to convey condensed water existing in the water tank to a proper temperature zone in the condensed water system, and working medium and energy are recovered.

In the existing common coal-fired power plant flue gas carbon dioxide capturing technology, most of the drainage water of the boiler system steam is directly discharged and is sent to a trench for discharge or to a unit drainage tank, and the drainage water is shown in figure 2. The disadvantage of this solution is that:

1. The quality of the steam condensate water is equivalent to that of desalted water, and the desalted water is discharged to a trench or a unit drainage tank to be mixed with industrial water. The water quality of the industrial water is treated to the desalted water quality by the water treatment system for recycling, so that the water treatment cost is increased;

2. The temperature of the conventional condensed water is about 100 ℃, and the condensed water is discharged to a trench or a unit drainage tank system, so that a large amount of cooling water is required to be mixed for reducing water vapor loss and visual pollution and protecting equipment such as pumps from being scalded. The total loss of energy possessed by the condensed water increases the complexity of the system. Specifically, the enthalpy value of 0.3MPa steam is 2738kJ/kg, the enthalpy value of saturated water at the same pressure is 604kJ/kg, and the heat of the saturated water accounts for 22% of that of the saturated steam.

3. The conventional coal-fired power plant flue gas carbon dioxide trapping technology is relatively suitable for a flue gas carbon dioxide trapping system with moderate scale, and when the trapping scale is further enlarged, for example, 50-100 ten thousand tons per year has great influence on ditches, unit drainage tanks and the like, and is not beneficial to a large-scale coal-fired power plant flue gas carbon dioxide trapping system.

4. The steam trap is arranged, so that the fault rate of the steam trap is high.

5. The system is complex, and a drainage expansion vessel is required to be arranged for expansion, and a cooling water system is required to be arranged for cooling.

Disclosure of Invention

The application aims to provide a drainage integrated boiler for carbon dioxide trapping, and a drainage system comprising the drainage integrated boiler, wherein working medium and energy are recovered simultaneously according to the characteristics of a large-scale flue gas carbon dioxide trapping system of a coal-fired power plant, and the drainage integrated boiler with the drainage integrated function and the drainage system are arranged.

The application discloses a hydrophobic integrated boiler for capturing carbon dioxide, which comprises: a boiler body and a drain tank body, wherein,

The drainage integrated boiler comprises a liquid inlet arranged on the first end socket, a liquid outlet arranged on the second end socket, a steam inlet and a liquid outlet arranged on the side wall of the shell;

The boiler body is configured to: providing a place for heat exchange between the amine solution and water vapor;

The drain tank is arranged close to the second end socket side and positioned below the boiler body, and is configured to store liquefied water vapor.

In a preferred embodiment, the storage capacity of the drain tank is in the range of 1.5-5 tons.

The application also discloses a hydrophobic system for carbon dioxide capture, comprising: a hydrophobic integrated boiler as described hereinbefore; further comprises: a drain pump and a valve;

The liquid inlet of the drainage integrated boiler is connected with the desorption tower;

The drain tank body of the drain integrated boiler is connected to one or more drain pumps through a valve; when the number of the drainage pumps is a plurality of the drainage pumps, the drainage pumps are arranged in parallel; the drain pump is configured to pump condensed water vapor to a plant condensed water system or unit drain tank.

In a preferred embodiment, the water vapor flow rate of the hydrophobic system is in the range of 18-30 tons/hour.

In a preferred embodiment, the hydrophobic integrated boiler is arranged vertically or horizontally.

In a preferred embodiment, the bottom of the integrated hydrophobic boiler is at least 5 meters from the hydrophobic pump in the vertical direction.

In a preferred embodiment, the drainage pump is arranged on the ground, or in a negative-excavation arrangement.

The application also discloses a hydrophobic system for carbon dioxide capture, comprising: a boiler, a drain tank; further comprises: a drain pump and a valve;

the liquid inlet of the boiler is connected with the desorption tower, and the liquid outlet is connected with the drain tank;

The drain tank is connected to one or more drain pumps through a valve; when the number of the drainage pumps is a plurality of the drainage pumps, the drainage pumps are arranged in parallel; the drain pump is configured to pump condensed water steam to a plant condensed water system or a unit drain tank;

The distance between the drain tank and the drain pump in the vertical direction is at least 5 meters.

The application has at least the following technical effects:

(1) A drain tank is arranged below the boiler and can be integrally arranged with the boiler or connected with a pipeline in the middle;

(2) The boiler is tubular or plate-type, and can be horizontal or vertical;

(3) The amine working medium side of the boiler is connected with the absorption tower, and the inlet and outlet heights meet the process requirements of the absorption tower;

(4) A water storage space or an independent drain tank is arranged at the lower part of the boiler;

(5) And a drain pump is arranged to send high-temperature condensed water in the drain tank to a condensed water system or a condensed water or water supply system such as a low-pressure heater, a deaerator and the like, and a closed system is adopted without a flash tank.

(6) The height difference between the drain tank and the water pump meets the cavitation prevention requirement of the drain pump, and the drain pump is preferably arranged on the ground; the method can also adopt a negative excavation arrangement mode when the field is insufficient;

(7) One or more hydrophobic pump sets can be provided.

The numerous technical features described in the description of the present application are distributed among the various technical solutions, which can make the description too lengthy if all possible combinations of technical features of the present application (i.e., technical solutions) are to be listed. In order to avoid this problem, the technical features disclosed in the above summary of the application, the technical features disclosed in the following embodiments and examples, and the technical features disclosed in the drawings may be freely combined with each other to constitute various new technical solutions (which should be regarded as having been described in the present specification) unless such a combination of technical features is technically impossible. For example, in one example, feature a+b+c is disclosed, in another example, feature a+b+d+e is disclosed, and features C and D are equivalent technical means that perform the same function, technically only by alternative use, and may not be adopted simultaneously, feature E may be technically combined with feature C, and then the solution of a+b+c+d should not be considered as already described because of technical impossibility, and the solution of a+b+c+e should be considered as already described.

Drawings

FIG. 1 is a schematic diagram of a CO2 capture system architecture according to the prior art;

FIG. 2 is a schematic diagram of a boiler for carbon dioxide capture, and its hydrophobic system, according to the prior art;

FIG. 3 is a schematic structural diagram of a hydrophobic system for carbon dioxide capture according to one embodiment of the present application;

FIG. 4 is a schematic structural view of a hydrophobic system for carbon dioxide capture according to another embodiment of the present application;

Reference numerals illustrate:

1-induced draft fan; 2-a rich liquid pump; 3-lean liquid pump; 4-lean-rich liquid exchanger; a 5-solution boiler; a 6-regenerator; 7-a lean liquor cooler; 8-an absorption tower; 9-steam trap; 10-a hydrophobic diffusion vessel; 11-a drainage pump; 12-a drain tank; 13-valve regulating.

Detailed Description

Through extensive and intensive research, the inventor provides a carbon dioxide trapping system boiler with a drain tank and a drain system, which can recover drain water in large-scale carbon dioxide trapping engineering, and simultaneously recover energy and working medium, and a matched drain pump is reliable, so that a large amount of energy sources can be saved, and conditions are created for popularization and application of the carbon dioxide trapping engineering (CCUS).

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be understood by those skilled in the art that the claimed application may be practiced without these specific details and with various changes and modifications from the embodiments that follow.

Terminology

Carbon dioxide capture and utilization sequestration technology (CCUS): carbon dioxide capture technology is used to remove carbon dioxide from gas streams or to separate carbon dioxide as a gaseous product (carbon capture and storage, CCS technology for short). The power industry is the primary field of CCS technology application, with carbon dioxide released by fossil fuel combustion being the primary greenhouse gas source, with the largest emissions from the power generation industry. The trapping technology is a trapping technology of carbon dioxide in flue gas of a coal-fired power plant by adopting an absorption method.

Reboiler: the reboiler (boiler) is as the name implies, to vaporize the liquid once more. Its structure is almost similar to that of condenser, but condenser is used for cooling, and reboiler is used for heating and vaporization. The materials are heated and expanded or even vaporized in a reboiler (a boiler), the density is reduced, and the materials leave the vaporization space and smoothly return to the tower, the gas phase and the liquid phase in the tower return, the gas phase passes through the tower tray upwards, and the liquid phase can fall to the bottom of the tower. The bottom of the column will constantly be replenished with the evaporated liquid level due to the static pressure difference.

Cavitation: and when the local pressure in the liquid is reduced, the formation, development and collapse of cavities (cavitation) of vapor or gas in the liquid or at the liquid-solid interface are carried out. Cavitation can cause damage to the pump, especially considering cavitation for working media near saturation temperatures; cavitation margin is required in pump design.

The following outline of some of the innovative features of embodiments of the present application:

The carbon dioxide trapping system boiler with the drainage integrated function and the drainage system are shown in the figure 3, the system is used for a large-scale flue gas carbon dioxide trapping system of a coal-fired power plant, the boiler with the drainage integrated function is arranged, and the drainage of 3-5min can be stored in the boiler. The amine working medium side of the boiler is connected with the desorption tower, so that the requirement of the amine working medium on the circulating elevation is met. Meanwhile, the lower part of the boiler keeps a certain height from the ground, and the height difference between the lower part of the boiler and the drain pump is more than 5m, so that the cavitation allowance requirement of the drain pump is met. And a drainage pump is arranged on the ground to recycle the condensed water to a thermodynamic system such as a low-pressure oxygen remover or the like of the coal-fired power plant, and meanwhile, the complete recycling of working media and heat is realized.

The system fully utilizes the lower space of the boiler and is provided with a drainage storage tank. The condensed water and the upper heat exchange steam keep the same pressure, and the capacity expansion of the expander is not needed in the follow-up process; the saturated water with pressure is stored in the drainage storage tank, and a certain height difference is kept with the drainage pump, so that the cavitation prevention requirement of the drainage pump is met. The steam of the coal-fired power plant flue gas carbon dioxide trapping system is recovered to drain, and meanwhile, working media and energy are recovered, so that good benefits are achieved. Creating conditions for popularization and application of carbon dioxide trapping engineering (CCUS).

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Example 1,

The hydrophobic integrated boiler for carbon dioxide capture is shown in fig. 3 and comprises: the integrated drainage boiler comprises a boiler body 5 and a drainage tank body 12, wherein the drainage integrated boiler comprises a liquid inlet positioned at a first end socket and a liquid outlet positioned at a second end socket and is used for flowing in and out an amine solution; the liquid inlet is connected with the desorption tower. The integrated boiler also comprises a steam inlet and a steam outlet which are positioned on the side wall of the shell. In the upright arrangement, the steam inlet is located below the air outlet. The boiler body is configured to provide a location for heat exchange of the amine solution with the water vapor. The drain tank is arranged near the second end socket side and below the boiler body, and is configured to store liquefied water vapor. The drain tank can store 5 minute capacity of condensed water, i.e. 2.5 tons, calculated as the water vapor flow rate is 30 tons/hour, i.e. 0.5 tons/minute.

The drainage system comprises the drainage integrated boiler; further comprises: a plurality of drain pumps 11 and a valve regulating valve 13. The drain tank body of the drain integrated boiler is connected to a plurality of drain pumps which are connected in parallel through a valve. The drain pump is configured to pump condensed water vapor to a plant condensed water system or unit drain tank.

The drain pump is arranged on the ground, and the distance between the bottom of the drain integrated boiler and the drain pump in the vertical direction is 5 meters, and the height difference is the minimum height difference for ensuring that cavitation does not occur on the drain pump.

EXAMPLE 2,

In this embodiment, the boiler and the drain tank are separately arranged, as shown in fig. 4, the drain system comprising: a boiler 5, a drain tank 12; further comprises: a drain pump 11 and a valve regulating valve 13. The liquid inlet of the boiler 5 is connected with the desorption tower, and the liquid outlet is connected with the drain tank 12. The drain tank 12 is connected to a plurality of drain pumps 11 which are connected in parallel through a valve; the drain pump 11 is configured to pump condensed water vapor to a plant condensed water system or unit drain tank.

The drain pump 11 is arranged by negative digging, and the distance between the bottom of the drain integrated boiler and the drain pump 11 in the vertical direction is 5 meters, and the height difference is the minimum height difference for ensuring that cavitation does not occur in the drain pump.

It should be noted that in the present patent application, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. In the present patent application, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, and two cases are included: the act is performed solely on the basis of the element and is performed on the basis of the element and other elements. Multiple, etc. expressions include 2, 2 times, 2, and 2 or more, 2 or more times, 2 or more.

This specification includes combinations of the various embodiments described herein. Separate references to "one embodiment" or a particular embodiment, etc., do not necessarily refer to the same embodiment; however, unless indicated as mutually exclusive or as would be apparent to one of skill in the art, the embodiments are not mutually exclusive. It should be noted that the term "or" is used in this specification in a non-exclusive sense unless the context clearly indicates otherwise or requires otherwise.

All references mentioned in this disclosure are to be considered as being included in the disclosure of the application in its entirety so that modifications may be made as necessary. Further, it is understood that various changes or modifications of the present application may be made by those skilled in the art after reading the above disclosure, and such equivalents are intended to fall within the scope of the application as claimed.

Claims (8)

1. A hydrophobic integrated boiler for carbon dioxide capture, comprising: a boiler body and a drain tank body, wherein,

The drainage integrated boiler comprises a liquid inlet arranged on the first end socket, a liquid outlet arranged on the second end socket, a steam inlet and a liquid outlet arranged on the side wall of the shell;

The boiler body is configured to: providing a place for heat exchange between the amine solution and water vapor;

The drain tank is arranged close to the second end socket side and positioned below the boiler body, and is configured to store liquefied water vapor.

2. The integrated hydrophobic boiler of claim 1, wherein the storage capacity of the hydrophobic tank ranges from 1.5 tons to 5 tons.

3. A hydrophobic system for carbon dioxide capture, comprising: a hydrophobic integrated boiler as claimed in any one of claims 1 or 2; further comprises: a drain pump and a valve;

The liquid inlet of the drainage integrated boiler is connected with the desorption tower;

The drain tank body of the drain integrated boiler is connected to one or more drain pumps through a valve; when the number of the drainage pumps is a plurality of the drainage pumps, the drainage pumps are arranged in parallel; the drain pump is configured to pump condensed water vapor to a plant condensed water system or unit drain tank.

4. A hydrophobic system as claimed in claim 3 wherein the hydrophobic system has a water vapour flow rate in the range 18-30 tons/hour.

5. A hydrophobic system as claimed in claim 3 wherein the hydrophobic integrated boiler is arranged vertically or horizontally.

6. A hydrophobic system as claimed in claim 3 wherein the bottom of the hydrophobic integrated boiler is at least 5 metres from the hydrophobic pump in a vertical direction.

7. A drainage system according to claim 3, wherein the drainage pump is arranged at the surface, or in a negative-displacement arrangement.

8. A hydrophobic system for carbon dioxide capture, comprising: a boiler, a drain tank; further comprises: a drain pump and a valve;

the liquid inlet of the boiler is connected with the desorption tower, and the liquid outlet is connected with the drain tank;

The drain tank is connected to one or more drain pumps through a valve; when the number of the drainage pumps is a plurality of the drainage pumps, the drainage pumps are arranged in parallel; the drain pump is configured to pump condensed water steam to a plant condensed water system or a unit drain tank;

The distance between the drain tank and the drain pump in the vertical direction is at least 5 meters.