CO2 mineralization curing method and curing system for aerated blocks coupled with power plants

Abstract

The application discloses a CO2 mineralization curing method and curing system for aerated blocks coupled with power plants, and the CO2 mineralization curing method for aerated blocks coupled with power plants comprises the following steps: S1, connecting the 180-200 DEG C waste heat steam of the power plant to steam cure the aerated blocks after demolding; and S2, performing CO2 gradient mineralization curing on the aerated blocks after the steam curing, wherein the CO2 mineralization is divided into N-stage mineralization curing zones with the temperature of the aerated blocks decreasing in stages; the high-temperature aerated blocks after the steam curing enter the N-stage mineralization curing zones from the first-stage mineralization curing zone in sequence; the high-pressure CO2 enters the waste heat recovery system after decompression, exchanges heat with the steam tail gas, and then enters each stage of the mineralization curing zone in sequence according to the order of the temperature of the aerated blocks in the mineralization curing zone from low to high to perform reverse mineralization reaction, and finally enters the waste heat recovery system after the first-stage mineralization curing zone. Compared with the prior art, the multi-stage mineralization curing zone cooperates with the reverse mineralization process, the CO2 utilization rate is effectively improved, the carbon curing cost is significantly reduced compared with the traditional curing mode, energy saving and emission reduction and production cost optimization are realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of carbon mineralization utilization of secondary curing, and particularly relates to a large-scale stepped mineralization curing system and method for aerated blocks. BACKGROUND

[0002] The existing mineralization curing process for aerated blocks, aerated concrete and other porous building materials generally adopts a segmented system scheme of "high-temperature steam curing-carbon capture CO2 mineralization", that is, the initial structure is formed by high-temperature steam curing to promote the hydration of cementitious materials, and then the product is transferred to a mineralization reaction space for CO2 permeation carbonization. However, the separated system architecture has multiple systemic shortcomings in actual operation: from the process connection level, the product after high-temperature steam curing needs to go through slow cooling to reach a temperature suitable for carbonization curing, resulting in a prolonged curing period and a large amount of heat loss in the link conversion, thus low energy utilization efficiency; from the reaction condition adaptability perspective, the high-humidity and high-temperature environment formed by steam curing is naturally in conflict with the low-humidity and normal-temperature conditions required for CO2 mineralization, which reduces the diffusion rate of CO2 in the product pores and limits the carbonation reaction depth; from the system energy efficiency design, the existing process flow has low energy utilization rate, which is difficult to meet the economic requirements of industrial production.

[0003] The root cause of the above problems lies in the lack of overall design of "building material preparation-mineralization reaction-energy cycle" in the existing system scheme, which fails to build a system that coordinates the curing process and heat recovery and utilization. With the urgent demand for low-carbon and large-scale production in the building material industry, it is urgent to rebuild a new mineralization curing technology scheme that integrates mineralization curing and energy recovery and utilization from the perspective of system engineering, to realize the coordinated optimization of CO2 fixation efficiency, building material performance improvement and system economy. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a CO2 mineralization curing method and curing system for aerated blocks coupled with a power plant, to solve the problem of low energy utilization rate and high secondary curing carbon curing cost in the use of CO2 mineralization curing for aerated blocks and concrete blocks.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] The present application first provides a CO2 mineralization curing method for aerated blocks coupled with a power plant, comprising:

[0007] S1, connecting the 180-200 DEG C waste heat steam of the power plant to steam cure the blocks after demolding;

[0008] S2, CO2 stepped mineralization curing of the blocks after steam curing, comprising:

[0009] S21, the CO2 mineralization is divided into N-stage mineralization curing zones with the temperature of the blocks in the zones decreasing in stages, N≥2, the temperature of the blocks in the first-stage mineralization curing zone is the highest, and the temperature of the blocks in the N-stage mineralization curing zone is the lowest;

[0010] S22, the high-temperature blocks after steam curing are sequentially sent into the N-stage mineralization curing zones from the first-stage mineralization curing zone; the high-pressure CO2 is sent into each stage of the mineralization curing zones in sequence after heat exchange with the steam tail gas in the waste heat recovery system, and finally sent into the waste heat recovery system after the first-stage mineralization curing zone; the reverse mineralization is opposite to the flow direction of CO2 and the conveying direction of the blocks.

[0011] The CO2 concentration in each stage of the N-stage mineralization curing zones changes in stages, the CO2 concentration in the N-stage mineralization curing zone is the highest, and the CO2 concentration in the first-stage mineralization curing zone is the lowest; the CO2 pressure in each stage of the mineralization curing zones is lower than 0.1 MPa;

[0012] During the CO2 staged mineralization curing process, the CO2 concentration, pressure and temperature in each stage of the mineralization curing zones are detected in real time, the gas flow is accelerated by the fan to enhance heat exchange and reaction; when the CO2 pressure in each stage of the mineralization curing zones is lower than the preset value, the CO2 is supplemented by the booster pump; when the gas pressure is higher than the set value, the exhaust device is used for exhaust.

[0013] The CO2 concentration in the N-stage mineralization curing zone is 80%, and the CO2 concentration in the first-stage mineralization curing zone is 60%.

[0014] The CO2 pressure in each stage of the mineralization curing zones is 0.09 MPa.

[0015] The residence time of the blocks in each stage of the mineralization curing zones is 8 h, and the total curing time is 16 h.

[0016] The application also provides a CO2 mineralization curing system for aerated blocks coupled with a power plant, comprising:

[0017] A steam curing device is connected to the 180-200 ℃ waste heat steam of the power plant and used for steam curing of the demolded blocks;

[0018] A CO2 gas tank is used for providing a CO2 gas source;

[0019] A pressure reducing device is used for reducing the pressure of the CO2 gas output by the CO2 gas tank;

[0020] A waste heat recovery system comprises a first heat exchange flow channel and a second heat exchange flow channel;

[0021] The CO2 gradient mineralization curing device comprises N-stage mineralization curing zones with gradient decrease of block temperature, N≥2, the block temperature is the highest in the first-stage mineralization curing zone and the block temperature is the lowest in the N-stage mineralization curing zone; the steam-cured block is subjected to CO2 mineralization curing from the first-stage mineralization curing zone to the N-stage mineralization curing zone to form a finished product.

[0022] The trolley is used for transporting the blocks, including feeding and discharging the steam curing device, feeding and discharging the CO2 gradient mineralization curing device and moving in the steam curing device and the CO2 gradient mineralization curing device.

[0023] The decompressed CO2 gas enters the first flow channel of the waste heat recovery system; the low-temperature steam output from the steam curing device enters the second flow channel of the waste heat recovery system and exchanges heat with the CO2 gas to be discharged in the form of tail gas; the decompressed CO2 gas exchanges heat with the low-temperature steam to be warmed and flow out; the warmed CO2 gas flows out reversely from the N-stage mineralization curing zone of the CO2 gradient mineralization curing device and is finally discharged from the first-stage mineralization curing zone, and the CO2 tail gas after being discharged enters the first flow channel of the waste heat recovery system to participate in heat exchange.

[0024] The CO2 gradient mineralization curing device adopts a non-open-air type pressure curing room; the inside of the non-open-air type pressure curing room is divided into curing zones and waiting zones, the waiting zones include entry and exit waiting zones, and two isolation doors are arranged at the entrance and exit of the non-open-air type pressure curing room.

[0025] The non-open-air type pressure curing room adopts a steel structure frame, a rock wool insulation layer is arranged on the roof and four walls, and anti-skid concrete is poured on the ground to form a closed space; an air blower system is arranged in the closed space to maintain stable internal air pressure; the inside of the closed space is divided into a middle curing zone and entry and exit waiting zones arranged on both sides; the air blower system comprises an air supply pump and an exhaust device, the air supply pump is linked with an emergency button, when the emergency button is started, the air supply pump is opened and all the entrance and exit doors are opened; the exhaust device is linked with an air pressure detection system in the curing room, when the air pressure in the curing room is higher than a set value, the exhaust device is started until the air pressure reaches a preset value.

[0026] The non-open-air type pressure curing room adopts a gas film space structure, the gas film space structure is composed of a high-strength flexible film material to form a closed space; an air blower system is arranged in the gas film space structure to maintain stable internal air pressure, and the inside of the gas film space structure is divided into a middle curing zone and entry and exit waiting zones arranged on both sides; the air blower system comprises an air supply pump and an exhaust device, the air supply pump is linked with an emergency button, when the emergency button is started, the air supply pump is opened and all the entrance and exit doors are opened; the exhaust device is linked with an air pressure detection system in the curing room, when the air pressure in the curing room is higher than a set value, the exhaust device is started until the air pressure reaches a preset value.

[0027] The control mode of the two isolation doors is that when the product to be maintained enters the maintenance room, the outer door is opened and the inner door is closed, then the outer door is closed and the inner door is opened after the product enters the warehouse waiting area, so that the product enters the maintenance area, when the maintained product leaves the maintenance room, the outer door is closed and the inner door is opened, then the inner door is closed and the outer door is opened after the product enters the warehouse waiting area, so that the product leaves the maintenance room and the outer door is closed.

[0028] Compared with the prior art, the beneficial effects of the present application are that:

[0029] 1. In the method, the high-temperature blocks after steam curing are subjected to heat exchange with low-temperature CO2 generated in the first curing through a waste heat recovery system, so as to realize rapid cooling and pre-curing of the block surface; in the Nth curing area, the blocks are subjected to carbonization curing by using high-temperature CO2 generated by the waste heat recovery system, so as to ensure that the blocks are in the best curing temperature range. The multi-stage mineralization curing area cooperates with the reverse mineralization process to effectively improve the CO2 utilization rate, significantly reduce the carbon curing cost compared with the traditional curing mode, and realize energy saving and emission reduction and production cost optimization.

[0030] 2. The method couples the flow direction of CO2 and the running direction of aerated blocks in reverse, so as to realize reverse matching of the CO2 temperature and the block temperature. After steam curing, the low-temperature CO2 contacts the high-temperature blocks to complete rapid cooling and pre-carbonization, so as to avoid the influence of temperature sudden change on the performance of the blocks; in the later curing stage, the high-temperature CO2 is combined with the cooled blocks to realize deep curing at the best temperature. The reverse coupling design realizes energy cascade utilization, improves energy utilization efficiency, and at the same time, significantly improves the carbon sequestration rate and carbonization depth, effectively enhances the strength and durability of the blocks, and improves the product quality.

[0031] 2. The multi-stage mineralization curing area arranged in stages increases the mineralization space of the blocks, so as to expand the scale of CO2 mineralization curing of aerated blocks, concrete blocks and the like, and through the large-scale pressure curing room and the automatic handling system, large batches of blocks can be simultaneously subjected to mineralization curing, the residence time of the blocks in the CO2 atmosphere is increased, and the carbon sequestration depth and strength are significantly enhanced.

[0032] 3. The adaptability of the mineralization reaction conditions is improved. Through the coupling of steam curing and two-curing carbon cascade curing, the inhibition of high temperature of the traditional reaction kettle to the formation of carbonate is avoided, more suitable temperature conditions for mineralization reaction are provided, and the carbon sequestration amount, carbon sequestration depth, strength and curing efficiency are improved.

[0033] 4. The pressure of two-curing carbon mineralization curing is improved, the problems of low CO2 concentration and insufficient pressure in the open air or open environment are solved, the set pressure meets the requirements of pressure vessel regulations, industrial implementation is facilitated, and the carbon sequestration effect is further improved.

[0034] 5. The safety of mineralization maintenance is improved, intelligent control system and trackless flat carrier are used in the whole process, no personnel is needed during the operation of the maintenance house, which saves labor and ensures the safety of the operators. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A flow chart of the CO2 mineralization maintenance method for aerated blocks coupled with a power plant is provided in the examples.

[0036] Figure 2 Schematic diagram of CO2 maintenance area. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions and advantages of the present application clearer and more intelligible, the following describes the present application through specific examples shown in the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0038] The present application will be further described in detail below with reference to the accompanying drawings. The following examples are an explanation of the present application, and the present application is not limited to the following examples.

[0039] The present embodiment provides a CO2 mineralization maintenance method for aerated blocks coupled with a power plant, as shown in Figure 1 The steps include:

[0040] (1) Steam curing of the demolded blocks:

[0041] Steam curing can be performed in a steam curing kettle.

[0042] After the blocks are formed and demolded, they are transported by a carrier to a steam curing kettle for steam curing. The steam curing kettle is connected to the 180-200 ℃ waste heat steam of the power plant. The steam curing is maintained for 4 h, and the steam tail gas is connected to the waste heat recovery system through a pipeline.

[0043] (2) CO2 gradient mineralization maintenance of the steam-cured blocks:

[0044] In the CO2 gradient mineralization maintenance process, the CO2 mineralization is divided into N-stage mineralization maintenance areas with a gradient decrease in block temperature, N≥2. The block temperature is highest in the first-stage mineralization maintenance area and lowest in the N-stage mineralization maintenance area.

[0045] A pressure maintenance house can be used for CO2 mineralization maintenance.

[0046] The high-temperature blocks after steam curing are transported to the pressure curing room and sequentially enter the Nth mineralization curing zone from the first mineralization curing zone; the high-pressure CO2 enters the waste heat recovery system after decompression, exchanges heat with the steam tail gas, and then sequentially enters each mineralization curing zone in the order of block temperature from low to high, and finally enters the waste heat recovery system after the first mineralization curing zone. The reverse mineralization is opposite to the flow direction of CO2 and the conveying direction of the blocks.

[0047] The waste heat recovery system adopts a tubular heat exchanger with a heat exchange area of 50 m 2 .

[0048] Taking the two-stage mineralization curing as an example, the specific process is as follows:

[0049] 1. The high-pressure CO2 is reduced to 0.15 MPa by the decompression device and enters the tubular heat exchanger to exchange heat with the steam tail gas and the first-stage curing zone tail gas in countercurrent to be heated to 60 ℃;

[0050] 2. The heated CO2 sequentially enters the second-stage curing zone (CO2 concentration 80%, block surface temperature 50-80 ℃) and the first-stage curing zone (CO2 concentration 60%, block surface temperature 130-150 ℃), and stays for 4 h in each stage, with a total curing time of 8 h;

[0051] The circulating fans of the mineralization curing zones automatically adjust the frequency according to the CO2 concentration difference (high-frequency operation when the concentration difference is greater than 10%, and low-frequency operation when the concentration difference is less than 5%) to ensure uniform distribution of CO2 concentration in the mineralization zone.

[0052] The embodiment provides a CO2 mineralization curing system for aerated blocks coupled with a power plant, comprising:

[0053] A steam curing device is used for steam curing of demolded blocks. The steam curing device can be a steam curing kettle.

[0054] A CO2 gas tank is used to provide a CO2 gas source.

[0055] A decompression device is used to decompress the CO2 gas output by the CO2 gas tank.

[0056] A waste heat recovery system comprises a first heat exchange flow channel and a second heat exchange flow channel.

[0057] A CO2 gradient mineralization curing device comprises N-stage mineralization curing zones with a gradient decrease in block temperature, N≥2, the first-stage mineralization curing zone has the highest block temperature, and the Nth-stage mineralization curing zone has the lowest block temperature. The blocks after steam curing sequentially enter the first-stage mineralization curing zone for CO2 mineralization curing, and finally enter the Nth-stage mineralization curing zone to complete CO2 mineralization curing to form finished products.

[0058] The transport vehicle is used for transporting the blocks, and includes steam curing device feeding and discharging and CO2 gradient mineralization curing device feeding and discharging.

[0059] The steam curing device, the waste heat recovery system and the CO2 gradient mineralization curing device are coupled, and specifically, the decompressed CO2 gas enters the first flow channel of the waste heat recovery system; the low-temperature steam output by the steam curing device enters the second flow channel of the waste heat recovery system and exchanges heat with the CO2 gas and is discharged in the form of tail gas; the decompressed CO2 gas exchanges heat with the low-temperature steam and flows out after being warmed up; the CO2 gas flowing out after being warmed up enters the Nth mineralization curing area of the CO2 gradient mineralization curing device in reverse, and is finally discharged from the first mineralization curing area; and the CO2 tail gas after being discharged enters the first flow channel of the waste heat recovery system to participate in heat exchange.

[0060] In order to ensure the safety of the whole mineralization curing system, the mineralization curing system further comprises a safety guarantee system.

[0061] The safety guarantee system comprises:

[0062] (1) Emergency ventilation device: an air supply pump (air volume 20000 m 3 / h) is hard-wired connected with an emergency button with a distance of less than 30 m, and the inlet and outlet doors are completely opened within 10 s after the emergency ventilation device is triggered and started within 0.5 s;

[0063] (2) Air pressure balancing device: a pneumatic butterfly valve is linked with a pressure transmitter, and when the air pressure exceeds 0.11 MPa, the air pressure is released at a rate of 0.005 MPa / s until the air pressure is 0.09 MPa and the air pressure balancing device is closed.

[0064] The steam curing device, the waste heat recovery system and the CO2 gradient mineralization curing device are coupled, and the efficiency, safety and economy of the CO2 mineralization curing can be significantly improved. The related parameters of the steam curing device, the waste heat recovery system and the CO2 gradient mineralization curing device can be adjusted according to actual production needs.

[0065] The CO2 gradient mineralization curing device adopts a non-open-air type pressure curing room. The pressure curing room can adopt two structural forms.

[0066] Structural form 1: a steel structure frame is adopted, a 100 mm rock wool insulation layer is arranged on the roof and the four walls, and anti-skid concrete is poured on the ground to form a closed space with a length of 70 m, a width of 20 m and a height of 3 m, and the inside is divided into a middle curing area with a size of 50 m*20 m*3 m, and two side waiting areas with a size of 10 m*20 m*3 m each for entering and leaving the warehouse;

[0067] Structural form 2: a gas film space structure is adopted, which is composed of high-strength flexible film material and is equipped with a special fan system to maintain stable internal air pressure, and the space is divided in the same way as embodiment 1.

[0068] The pressure curing room has two steel isolation doors (4 m wide x 3 m high) at the entrance and exit, which are equipped with pneumatic door closers and sealing rubber strips, and the interlocking sealing is realized through a PLC control system.

[0069] (1) When the product enters the warehouse, the outer door is opened after receiving the identification signal of the carrier, and the product enters the warehouse waiting area, then the outer door is closed, the system detects the sealing by the pressure fluctuation threshold ≤0.001 MPa, and opens the inner door after confirmation.

[0070] (2) When the product leaves the warehouse, the inner door is opened when the curing is completed and there is no product in the waiting area, and the product enters the warehouse waiting area, then the inner door is closed and the sealing is detected, and then the outer door is opened to release.

[0071] The CO2 pressure (gauge pressure) in the curing room is controlled through the booster pump and the pressure detection system:

[0072] (1) The booster pump inlet is connected to a 10 MPa high-pressure CO2 tank, and the outlet is connected to the curing room top gas supply pipeline through a pipeline;

[0073] (2) Pressure transmitters are installed at the four corners and the center of the curing room to collect pressure data in real time, and when the pressure of any measuring point is lower than 0.085 MPa, the control cabinet triggers the booster pump to start until the pressure rises to 0.09 MPa.

[0074] The product is transported by a trackless flat car with laser navigation and positioning function, which realizes the automatic transportation from the forming workshop→ warehouse waiting area→ curing area designated location→ warehouse waiting area→ finished product warehouse through system planning path.

[0075] From the energy point of view, the main difference between the normal curing scheme and the energy utilization rate of this scheme is calculated, and the calculation is simplified.

[0076] Let the specific heat capacity of the block be c qk =1.05 kJ / (kg·K), the mass m=100 kg, the initial temperature of the block after steam curing is T ini =150 ℃, and the final temperature after mineralization curing is T fin =70 ℃.

[0077] The initial temperature of CO2 in the normal curing scheme is 25 ℃, the specific heat capacity c CO2 =0.84 kJ / (kg·K), and the final temperature is 50 ℃; the initial temperature of CO2 in this scheme is 70 ℃, the specific heat capacity c CO2 =0.84 kJ / (kg·K), and the final temperature is 100 ℃

[0078] Then the heat release and heat absorption calculation:

[0079] Q = m·c·ΔT

[0080] The required CO2 mass is:

[0081] m CO2 =Q / (c CO2 ·ΔT CO2 )

[0082] Log mean temperature difference:

[0083] LMTD=(ΔT2-ΔT1) / ln(ΔT1 / ΔT2)

[0084]

[0085] The data in the table show that the countercurrent maintenance scheme of the application is significantly lower than the conventional maintenance scheme in terms of CO2 demand, and since the calculation is based on the assumption of a pure CO2 environment, the dynamic adjustment of the concentration in the step-by-step maintenance will further reduce the CO2 demand in actual engineering, significantly reducing equipment costs; although the log mean temperature difference of the concurrent scheme is larger, the temperature gradient is deeply matched by the countercurrent design of the present scheme, avoiding the heat exchange dead zone, and the outlet CO2 temperature is higher, the energy quality is significantly improved, which can be directly used for secondary heating or waste heat recovery, and has outstanding advantages in terms of material optimization, efficiency improvement and quality upgrading.

[0086] The above examples are only exemplary descriptions of the present application and do not limit its protection scope, and those skilled in the art can also make changes to it locally, as long as it does not exceed the spirit and essence of the present application, and is within the protection scope of the present application.

Claims

1. A method for CO2 mineralization curing of aerated concrete blocks coupled with a power plant, characterized in that, include: S1. Connect to the power plant's 180-200℃ waste heat steam for steam curing of the demolded blocks; S2. CO2 graded mineralization curing is applied to steam-cured blocks, including: S21. Divide CO2 mineralization into N-level mineralization curing zones with a stepped decrease in block temperature, where N≥2. The block temperature is highest in the first-level mineralization curing zone and lowest in the N-level mineralization curing zone. S22. After steam curing, the high-temperature blocks enter the Nth level mineralization curing zone sequentially from the first level mineralization curing zone. After depressurization, the high-pressure CO2 enters the waste heat recovery system and exchanges heat with the steam tail gas. Then, according to the block temperature in the mineralization curing zone from low to high, it enters each level mineralization curing zone sequentially for reverse mineralization reaction. Finally, after passing through the first level mineralization curing zone, it enters the waste heat recovery system. Reverse mineralization means that the flow direction of CO2 is opposite to the transport direction of the blocks.

2. The CO2 mineralization curing method for aerated concrete blocks according to claim 1, characterized in that, The CO2 concentration varies in a tiered manner within each level of the N-level mineralization conservation zone, with the highest CO2 concentration in the N-level zone and the lowest in the 1-level zone; the CO2 pressure within each level of the mineralization conservation zone is below 0.1 MPa. During the CO2 cascade mineralization curing process, the CO2 concentration, pressure, and temperature in each mineralization curing zone are monitored in real time. Fans are used to accelerate gas flow and enhance heat exchange and reaction. When the CO2 pressure in each mineralization curing zone is lower than the preset value, CO2 is supplemented by a booster pump. When the gas pressure is higher than the set value, exhaust is performed through an exhaust device.

3. The CO2 mineralization curing method for aerated concrete blocks according to claim 2, characterized in that, The CO2 concentration in the Nth-level mineralization conservation area is 80-100%, while the CO2 concentration in the first-level mineralization conservation area is 40-60%.

4. The CO2 mineralization curing method for aerated concrete blocks according to claim 2, characterized in that, The CO2 pressure in each mineralization maintenance zone is 0.09 MPa.

5. The CO2 mineralization curing method for aerated concrete blocks according to claim 1, characterized in that, The blocks remain in each mineralization curing zone for 4-6 hours, with a total curing time of 8-12 hours.

6. A CO2 mineralization curing system for aerated concrete blocks coupled with a power plant, characterized in that, include: The steam curing device is connected to the waste heat steam at 180-200℃ from the power plant and is used for steam curing of the demolded blocks. CO2 gas cylinders are used to provide a CO2 gas source; A pressure reducing device is used to reduce the pressure of CO2 gas output from a CO2 cylinder; The waste heat recovery system includes a first heat exchange channel and a second heat exchange channel; The CO2 stepped mineralization curing device includes N-stage mineralization curing zones where the block temperature decreases in a stepped manner, where N≥2. The block temperature is highest in the first-stage mineralization curing zone and lowest in the Nth-stage mineralization curing zone. After steam curing, the blocks undergo CO2 mineralization curing sequentially, starting from the first-stage mineralization curing zone and finally entering the Nth-stage mineralization curing zone to complete the CO2 mineralization curing and form the finished product. Transport vehicle for transporting blocks, including feeding and sending blocks into and out of steam curing units, feeding and sending blocks into and out of CO2 cascade mineralization curing units, and moving blocks within steam curing units and CO2 cascade mineralization curing units. After depressurization, the CO2 gas enters the first flow channel of the waste heat recovery system; the low-temperature steam output from the steam curing device enters the second flow channel of the waste heat recovery system and exchanges heat with the CO2 gas before being discharged as tail gas; the depressurized CO2 gas exchanges heat with the low-temperature steam and then flows out at a higher temperature; the CO2 gas that flows out at a higher temperature enters the Nth stage mineralization curing zone of the CO2 cascade mineralization curing device in the opposite direction and finally exits from the 1st stage mineralization curing zone. The discharged CO2 tail gas then enters the first flow channel of the waste heat recovery system to participate in heat exchange.

7. A CO2 mineralization curing system for aerated concrete blocks coupled with a power plant, as described in claim 6, is characterized in that... The CO2 cascade mineralization curing device adopts a non-open-air pressurized curing room; the non-open-air pressurized curing room is divided into a curing area and a waiting area, the waiting area includes an inbound waiting area and an outbound waiting area, and the inbound and outbound of the non-open-air pressurized curing room are equipped with two isolation doors.

8. A CO2 mineralization curing system for aerated concrete blocks coupled with a power plant, as described in claim 7, is characterized in that... The non-open-air pressurized curing room adopts a steel structure frame, with rock wool insulation layers on the roof and four walls, and anti-slip concrete poured on the ground to form a sealed space. A fan system is installed in the sealed space to maintain stable internal air pressure. The sealed space is divided into a central curing area and two waiting areas for entering / exiting the curing room on each side. The fan system includes an air supply pump and an exhaust device. The air supply pump is linked to an emergency button. When the emergency button is activated, the air supply pump starts and all inlet and outlet doors open. The exhaust device is linked to the air pressure detection system in the curing room. When the air pressure in the curing room is higher than the set value, the exhaust device starts and shuts off when the air pressure reaches the preset value.

9. A CO2 mineralization curing system for aerated concrete blocks coupled with a power plant, as described in claim 7, is characterized in that... The non-open-air pressurized curing chamber adopts an air-supported membrane structure, which is a sealed space composed of high-strength flexible membrane material. A fan system is installed within the air-supported membrane structure to maintain stable internal air pressure. The interior is divided into a central curing area and two waiting areas for entry / exit on either side. The fan system includes an air supply pump and an exhaust device. The air supply pump is linked to an emergency stop button; when the emergency stop button is activated, the air supply pump starts and all inlet and outlet doors open. The exhaust device is linked to an air pressure detection system within the curing chamber; when the air pressure inside the curing chamber exceeds a set value, the exhaust device starts and closes when the pressure reaches the preset value.

10. A CO2 mineralization curing system for aerated concrete blocks coupled with a power plant, as described in claim 7, is characterized in that... The control method of the two isolation doors is as follows: when the product to be cured enters the curing room, the outer door is opened and the inner door is closed. After the product enters the warehousing waiting area, the outer door is closed first and then the inner door is opened to allow the product to enter the curing area. When the cured product leaves the curing room, the outer door is closed and the inner door is opened. After the product enters the outbound waiting area, the inner door is closed first and then the outer door is opened to allow the product to leave the curing room before the outer door is closed.

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