SCO2 circulation and carbon capture coupled low-carbon reheating system and method

Abstract

The invention provides an SCO2 circulation and carbon capture coupled low-carbon reheating system and method, and the system comprises a heat source unit which is used for providing initial heat; the SCO2 circulating unit is connected with the heat source unit and used for doing work through the heat energy and discharging exhaust gas; the carbon capture unit is connected with the SCO2 circulating unit and is used for realizing capture and regeneration of carbon components in the carbon-containing tail gas by utilizing the heat of the exhaust gas; the reheat supply unit is connected with the carbon capture unit and is used for heating a heat supply medium by using the SCO2 exhaust gas passing through the carbon capture unit so as to realize external heat supply; wherein exhaust gas exhausted by the SCO2 circulation unit sequentially flows through the carbon capture unit and the reheat supply unit for heat release, and finally returns to the SCO2 circulation unit to complete working medium circulation; advanced treatment of carbon-containing tail gas is achieved through the carbon capture unit, captured carbon dioxide can be subjected to resource utilization or sealed storage, and the heat supply industry is promoted to develop towards the near-zero emission direction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy utilization and carbon emission reduction, and specifically relates to a low-carbon reheat system and method coupling SCO2 cycle and carbon capture. BACKGROUND

[0002] Current heating systems mostly rely on fossil fuel combustion or single waste heat recovery, and have problems of high carbon emission intensity and low energy utilization efficiency. Although carbon capture technology can reduce carbon emissions, it consumes a large amount of additional energy when operated alone, resulting in an increase in overall system energy consumption. The SCO2 cycle system has high energy conversion efficiency due to the characteristics of the working medium, but often faces waste of waste heat in the heat output link, and does not form synergy with the carbon emission reduction link.

[0003] In the prior art, SCO2 cycle and carbon capture are mostly operated independently, and the two lack effective coupling mechanisms, cannot simultaneously achieve efficient heating and deep low carbon, and are difficult to meet the current development needs of energy systems in terms of low carbon and high efficiency. SUMMARY

[0004] The purpose of the present application is to provide a low-carbon reheat system and method coupling SCO2 cycle and carbon capture, to solve the problems of high carbon emission of existing heating systems, waste of SCO2 cycle waste heat, and high energy consumption of carbon capture, to realize the synergistic optimization of SCO2 cycle energy utilization and carbon capture process, and to improve the low carbon and energy utilization efficiency of the reheat system.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is: In a first aspect, the present application provides a low-carbon reheat system coupling SCO2 cycle and carbon capture, comprising: a heat source unit for providing initial heat; an SCO2 cycle unit connected to the heat source unit for doing work on heat energy and discharging spent gas; a carbon capture unit connected to the SCO2 cycle unit for capturing and regenerating carbon components in carbon-containing tail gas using the heat of the spent gas; a reheat unit connected to the carbon capture unit for heating a heating medium using SCO2 spent gas that has passed through the carbon capture unit to achieve external heating; wherein the spent gas discharged by the SCO2 cycle unit successively flows through the carbon capture unit and the reheat unit to release heat, and finally returns to the SCO2 cycle unit to complete the working medium cycle.

[0006] Preferably, the SCO2 cycle unit comprises: an SCO2 heater for receiving heat from the heat source unit and heating the SCO2 working medium; SCO2 turbine connected to the SCO2 heater for work output using high temperature and high pressure SCO2 working fluid; SCO2 cooler for cooling the SCO2 exhaust gas from the reheating unit; SCO2 compressor for pressurizing the cooled SCO2 working fluid and sending it back to the SCO2 heater.

[0007] Preferably, the carbon capture unit comprises: absorption tower for introducing carbon-containing tail gas and capturing carbon components by absorbent; desorption tower for regenerating the carbon-rich absorbent; regeneration heat exchanger arranged between the SCO2 turbine outlet and the desorption tower, using SCO2 exhaust gas to provide heat for the desorption process.

[0008] Preferably, the reheating unit comprises: heating heat exchanger for receiving SCO2 exhaust gas from the carbon capture unit and exchanging heat with the heating medium; heating pipe network for delivering the heated heating medium to the heat utilization end.

[0009] Preferably, the heat source unit is one or a combination of industrial waste heat boiler, solar heat collection system, geothermal system or biomass combustion system.

[0010] Preferably, the mechanical work output by the SCO2 turbine is used to drive the generator to generate electricity or drive the industrial equipment to run.

[0011] Preferably, the heating medium is circulating water, heat conducting oil or air.

[0012] Preferably, the absorbent used in the absorption tower is one of alcohol amine solution, ammonia water or ionic liquid.

[0013] Preferably, a control system is further included for adjusting the operating parameters of the SCO2 cycle unit, the carbon capture unit and the reheating unit to realize multi-condition adaptive operation.

[0014] In a second aspect, the present application provides a low-carbon reheating method coupling SCO2 cycle and carbon capture, comprising the following steps: The heat source unit provides heat to the SCO2 cycle unit; The SCO2 cycle unit converts heat energy into work and discharges medium-low temperature exhaust gas; The exhaust gas first enters the carbon capture unit to provide heat for the desorption process, realizing carbon capture and absorbent regeneration; Subsequently, the exhaust gas enters the reheating unit to heat the heating medium and supply heat externally; After releasing heat, the exhaust gas is cooled, pressurized, and then returned to the SCO2 circulation unit to complete the cycle.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a low-carbon reheating system coupled with an SCO2 cycle and carbon capture. By deeply coupling the SCO2 cycle unit, the carbon capture unit, and the reheating unit, it achieves synergistic optimization of energy cascade utilization and carbon emission reduction, and has the following comprehensive beneficial effects: First, the system significantly improves energy efficiency and low-carbon performance. After the SCO2 cycle unit completes its work output, its waste heat is used to drive the desorption process of the carbon capture unit and the heating process of the reheating unit in sequence, realizing the three-level cascade utilization of energy. This avoids the problems of waste heat and high carbon capture energy consumption in traditional systems, improving overall energy efficiency by about 15-25%. At the same time, by integrating the carbon capture function, the carbon emission intensity of the system is directly reduced, so that the carbon emission reduction rate of the heating process can reach more than 60%. Secondly, the system has a compact structure and strong synergy. By using regeneration heat exchangers and heating heat exchangers, the heat of SCO2 exhaust gas is directly used for carbon capture and heating, eliminating the need for external heat sources and auxiliary heating equipment required by traditional carbon capture. This simplifies the system structure, reduces equipment investment and operation and maintenance costs, and reduces the equipment footprint by about 20-30%. Third, the system is flexible and adaptable. The heat source unit can be adapted to various clean energy sources such as industrial waste heat, solar energy, and geothermal energy to meet the low-carbon heating needs of different scenarios. The SCO2 working fluid has good heat transfer performance and stability, and is suitable for high-temperature and high-pressure conditions. Combined with the intelligent control system, it can achieve multi-condition adaptive adjustment to ensure stable operation of the system under load fluctuations. In addition, the technology has significant environmental benefits and promotion value. The carbon capture unit achieves deep treatment of carbon-containing exhaust gas, and the captured carbon dioxide can be utilized or stored as a resource, promoting the development of the heating industry towards near-zero emissions. The modular design of the system facilitates rapid deployment in scenarios such as industrial parks and regional energy stations, providing a feasible technical path for large-scale low-carbon heating. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the process involved in an embodiment of the present invention. Detailed Implementation

[0017] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0018] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0019] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0020] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0021] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0023] Example 1 This embodiment provides a low-carbon reheating system coupled with an SCO2 cycle and carbon capture, including an SCO2 cycle unit, a carbon capture unit, a reheating unit, and a heat source unit. Each unit forms a cooperative system through the coupling of energy flow and material flow. Specifically: The heat source unit provides heat to the SCO2 cycle unit; After the heat source unit converts the heat into work, the exhaust gas discharged by the SCO2 circulation unit enters the carbon capture unit and the reheating unit in sequence to release heat. After further processing, it returns to the SCO2 circulation unit to complete the SCO2 working fluid cycle. The carbon capture unit utilizes the heat of SCO2 exhaust gas to capture and regenerate carbon components in carbon-containing tail gas. The captured carbon components are transported out for storage, and the regenerated absorbent is recycled. The reheating unit uses the heat from the SCO2 exhaust gas after passing through the carbon capture unit to heat the heating medium, and then transports it to the heat-consuming end through the pipeline network to achieve reheating.

[0024] Example 2 Based on Example 1, this example provides a low-carbon reheating system coupled with SCO2 cycle and carbon capture. The SCO2 cycle unit includes an SCO2 heater, an SCO2 turbine, an SCO2 cooler, and an SCO2 compressor, wherein: The SCO2 heater receives heat from the heat source unit, heats the SCO2 working fluid to a specific state, and then sends it into the SCO2 turbine to do work; the exhaust gas discharged from the SCO2 turbine enters the carbon capture unit and the reheating unit in sequence. The SCO2 cooler cools the SCO2 exhaust gas after passing through the reheating unit, and the SCO2 compressor pressurizes the cooled SCO2 working fluid, returning it to the SCO2 heater to form a circulation loop.

[0025] In this embodiment, the SCO2 turbine performs work to drive a generator or other industrial equipment.

[0026] Example 3 Based on Example 1, this example provides a low-carbon reheating system coupled with SCO2 cycle and carbon capture. The carbon capture unit includes an absorption tower, a desorption tower, and a regeneration heat exchanger, wherein: The absorption tower receives carbon-containing tail gas, and carbon capture is achieved by the reaction of the absorbent in the absorption tower with the carbon components. The carbon-rich absorbent is then sent to the desorption tower. The regenerator receives the exhaust gas from the SCO2 turbine and transfers heat to the desorption tower, driving the carbon-rich absorbent to release carbon components. The carbon components released from the desorption tower are processed and then transported for storage, while the regenerated absorbent is returned to the absorption tower for recycling.

[0027] In this embodiment, the absorbent used in the absorption tower is one of an alcohol amine solution, ammonia, or an ionic liquid.

[0028] Example 4 Based on Example 1, this example provides a low-carbon reheating system coupled with SCO2 cycle and carbon capture. The reheating unit includes a heat exchanger and a heating network, wherein: The heat exchanger receives SCO2 exhaust gas from the carbon capture unit and exchanges heat with the heating medium. The heating network transports the heated heating medium to the heat-consuming end to complete the reheating process.

[0029] In this embodiment, the heat source unit is one or more combinations of an industrial waste heat boiler, a solar thermal collection system, a geothermal system, or a biomass combustion system.

[0030] The heating medium is circulating water, heat transfer oil, or air.

[0031] Example 5 In industrial waste heat utilization scenarios, this embodiment provides a low-carbon reheating system coupling SCO2 circulation and carbon capture, with the heat source unit being the high-temperature waste heat generated during industrial production. The high-temperature waste heat is first introduced into the SCO2 heater of the SCO2 circulation unit, heating the SCO2 working fluid to a suitable state, driving the SCO2 turbine to perform work (this work can be used to drive generators or other equipment). After performing work, the temperature of the SCO2 exhaust gas drops to a specific range and first enters the regeneration heat exchanger of the carbon capture unit, providing regeneration heat to the carbon-rich absorbent in the desorption tower, causing the absorbent to release carbon components. The carbon components are then compressed, dried, and transported to a storage facility. After completing heat transfer, the temperature of the SCO2 exhaust gas further decreases, and it then enters the heating heat exchanger of the reheating unit, exchanging heat with the circulating water in the heating network to heat the circulating water to a temperature meeting the heating demand. The heated circulating water is then transported through the network to industrial plants or surrounding residential areas for energy supply. The SCO2 exhaust gas, after releasing heat, enters the SCO2 cooler to cool to a specific temperature, and then is pressurized by the SCO2 compressor before returning to the SCO2 heater to re-enter the circulation.

[0032] During this process, the absorption tower of the carbon capture unit continuously receives carbon-containing exhaust gas generated from industrial production. The absorbent reacts fully with the carbon components in the exhaust gas to achieve carbon capture. The regenerated absorbent is then recycled back to the absorption tower, ensuring the continuous carbon capture process. The entire system achieves efficient recovery of industrial waste heat, deep carbon capture, and synergistic low-carbon heating, meeting the low-carbon energy utilization needs in industrial settings.

[0033] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A low-carbon reheat system coupled with SCO2 cycle and carbon capture, characterized in that, The application relates to a SCO2 cycle system for industrial waste heat recovery and carbon capture. The application comprises: a heat source unit for providing initial heat; a SCO2 cycle unit connected with the heat source unit for converting heat energy into work and discharging waste gas; a carbon capture unit connected with the SCO2 cycle unit for capturing and regenerating carbon components in carbon-containing tail gas by using the heat of the waste gas; a reheat unit connected with the carbon capture unit for heating a heat supply medium by using the SCO2 waste gas from the carbon capture unit to realize external heat supply; 2. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 1, characterized in that, wherein the waste gas discharged from the SCO2 cycle unit sequentially flows through the carbon capture unit and the reheat unit to release heat and finally returns to the SCO2 cycle unit to complete the working medium cycle. The SCO2 cycle unit comprises: a SCO2 heater for receiving the heat from the heat source unit and heating SCO2 working medium; a SCO2 turbine connected with the SCO2 heater for converting the energy of high-temperature and high-pressure SCO2 working medium into work; a SCO2 cooler for cooling the SCO2 waste gas from the reheat unit; 3. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 1, characterized in that, a SCO2 compressor for pressurizing the cooled SCO2 working medium and sending it back to the SCO2 heater. The carbon capture unit comprises: an absorption tower for introducing carbon-containing tail gas and capturing carbon components by using an absorbent; a desorption tower for regenerating the carbon-rich absorbent; 4. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 1, characterized in that, a regeneration heat exchanger arranged between the SCO2 turbine outlet and the desorption tower and using the SCO2 waste gas to provide heat for the desorption process. The reheat unit comprises: a heat supply heat exchanger for receiving the SCO2 waste gas from the carbon capture unit and exchanging heat with a heat supply medium; 5. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 1, characterized in that, a heat supply pipe network for delivering the heated heat supply medium to a heat consumption end.

6. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 2, characterized in that, The heat source unit is one or a combination of industrial waste heat boilers, solar heat collection systems, geothermal systems or biomass combustion systems.

7. The low-carbon reheat system coupled with carbon capture of claim 4, wherein, The mechanical work output by the SCO2 turbine is used to drive a generator to generate electricity or drive industrial equipment to run.

8. The low-carbon reheat system coupled with carbon capture of Claim 3, wherein, The heat supply medium is circulating water, heat conducting oil or air.

9. The low-carbon reheat system coupled with carbon capture by SCO2 cycle according to claim 1, characterized in that, The absorbent used in the absorption tower is one of alcohol amine solution, ammonia water or ionic liquid.

10. A low-carbon reheat method coupled with SCO2 cycle and carbon capture, characterized in that, A control system is further included for adjusting the operating parameters of the SCO2 cycle unit, the carbon capture unit and the reheat unit to realize multi-working condition adaptive operation. The application further comprises the following steps: the heat source unit provides heat to the SCO2 cycle unit; the SCO2 cycle unit converts heat energy into work and discharges medium and low temperature waste gas; the waste gas first enters the carbon capture unit to provide heat for the desorption process and realize carbon capture and absorbent regeneration; then the waste gas enters the reheat unit to heat the heat supply medium and supply heat externally; the waste gas after heat release is cooled, pressurized and returned to the SCO2 cycle unit to complete the cycle.

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