A Visual Experimental System for Direct Combustion of Supercritical Carbon Dioxide

Abstract

This invention discloses a visual supercritical carbon dioxide direct combustion experimental system, comprising a visual reactor system, a supercritical carbon dioxide supply system, an oxidizer supply system, a fuel supply system, a flue gas cooling and exhaust system, and a chiller unit. The visual reactor system consists of a reaction vessel and a viewing window, allowing observation of the high-temperature, high-pressure flame at the reactor center. The supercritical carbon dioxide supply system, oxidizer supply system, and fuel supply system inject carbon dioxide, oxidizer, and fuel into the visual reactor at set temperatures and pressures. The flue gas cooling and exhaust system rapidly cools the post-reaction flue gas to prevent secondary reactions. The chiller unit provides cooling water to the equipment requiring cooling throughout the system. This supercritical carbon dioxide direct combustion system allows for the study of flame morphologies of various fuels undergoing swirling and laminar combustion in a supercritical carbon dioxide environment, as well as the research on the combustion characteristics of fuels in supercritical carbon dioxide.

Description

Technical Field

[0001] This invention relates to the interdisciplinary field of energy efficiency utilization and environmental protection, specifically to a visual experimental system for direct combustion of supercritical carbon dioxide. Background Technology

[0002] Supercritical carbon dioxide power cycles, as a novel energy conversion method with enormous efficiency potential and broad application prospects, have attracted attention from academia and industry in recent years. Direct-heated carbon dioxide power cycles replace the heat source and heat exchanger in indirect-heated cycles with a combustion chamber, achieving heat-work conversion through the direct combustion reaction of fuel in an oxygen-rich atmosphere. Direct-heated cycles have two major advantages: First, direct-heated supercritical carbon dioxide cycles have higher turbine inlet temperatures, meaning higher cycle efficiency potential, which can be used to compensate for the energy consumed by air separation oxygen production units; second, direct-heated cycles have inherent carbon dioxide capture capabilities, eliminating the need for additional processes and energy for carbon dioxide capture. The direct combustion supercritical carbon dioxide cycle system represents a significant improvement over existing technologies in both total combustion pressure and carbon dioxide partial pressure. In particular, the carbon dioxide partial pressure has been increased from subcritical to supercritical. The changes in the physicochemical properties of the reaction atmosphere have a significant impact on fuel ignition, combustion process, and combustion characteristics. Furthermore, gas diffusion is slower in a supercritical carbon dioxide environment, and the actual carbon dioxide concentration is higher. The high temperature and high pressure environment under supercritical carbon dioxide atmosphere places high demands on the reactor, and conventional designs are difficult to visualize and observe the combustion of fuel in a supercritical carbon dioxide atmosphere. Summary of the Invention

[0003] The purpose of this invention is to provide a visual supercritical carbon dioxide direct combustion experimental system to solve the problem of difficulty in studying the combustion of fuels in a supercritical carbon dioxide atmosphere, and to realize the visual observation of the combustion characteristics of fuels in a supercritical carbon dioxide atmosphere.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A visual supercritical carbon dioxide direct combustion experimental system includes a visual reactor system, a supercritical carbon dioxide supply system, an oxidant supply system, a fuel supply system, and a flue gas cooling and exhaust system.

[0006] The visualization reactor system includes a reactor body, a visualization window, a burner, and a tail flue gas water-cooled dilution jacket outlet pipe; wherein, the supercritical carbon dioxide burner is located at the upper end of the reactor body, the visualization window is located on the reactor body, and the tail flue gas water-cooled dilution jacket outlet pipe is located at the lower end of the reactor body; the outlet flue gas is discharged after being diluted and cooled by the water-cooled dilution jacket.

[0007] The supercritical carbon dioxide supply system is connected to the supercritical carbon dioxide burner in the visualized reactor and is used to supply supercritical carbon dioxide to the supercritical carbon dioxide burner.

[0008] The oxidant supply system is connected to the supercritical carbon dioxide burner in the visualization reactor and is used to supply oxidant to the supercritical carbon dioxide burner.

[0009] The fuel supply system is connected to the supercritical carbon dioxide burner in the visualized reactor and is used to supply fuel to the supercritical carbon dioxide burner.

[0010] The flue gas cooling and discharge system is connected to the tail flue gas water-cooled dilution jacket outlet pipe in the visualized reactor and is used to treat the flue gas discharged from the reactor body.

[0011] Furthermore, the burners of the visualized reactor are either coaxial burners that simulate near-laminar flow or swirling burners that simulate strong turbulent mixing.

[0012] Furthermore, the reactor is equipped with an insulation layer and an electric heating layer. A coaxial burner is located at the upper end of the reactor body, and a tail flue gas water-cooled dilution jacket is installed at the lower end of the reactor body. The outlet flue gas is diluted and cooled by the water-cooled dilution jacket before being discharged. The reactor body is divided into an outer pressure-bearing shell and an internal heating element and insulation layer. A viewing window is opened on the reactor body wall and the insulation layer.

[0013] Furthermore, the supercritical carbon dioxide supply system includes a high-pressure carbon dioxide cylinder, a water-cooled storage tank, a first filter, a liquid booster pump, a first check valve, a high-pressure carbon dioxide mass flow meter, and a carbon dioxide preheater connected in sequence. The outlet of the high-pressure carbon dioxide cylinder is connected to the inlet of the water-cooled storage tank, the outlet of the water-cooled storage tank is connected to the liquid booster pump, the outlet of the liquid booster pump is connected to the inlet of the high-pressure carbon dioxide mass flow meter, the outlet of the high-pressure carbon dioxide mass flow meter is connected to the carbon dioxide preheater, and the outlet of the carbon dioxide preheater is connected to the carbon dioxide inlet of the visible reactor burner.

[0014] Furthermore, the oxidizing gas supply system includes an oxygen supply system and a carbon dioxide supply system, which are respectively connected to a mixing tank. The outlet of the mixing tank is connected to an oxidizing gas preheater, and the outlet of the oxidizing gas preheater is connected to the oxidizing gas inlet of the burner. The oxygen supply system includes a high-pressure oxygen cylinder, a second one-way valve, and an oxygen high-pressure mass flow meter connected in sequence, wherein the oxygen high-pressure mass flow meter is connected to the mixing tank. The carbon dioxide supply system includes a second high-pressure carbon dioxide cylinder, a third one-way valve, and a carbon dioxide mass flow meter connected in sequence, wherein the carbon dioxide mass flow meter is connected to the mixing tank and a one-way valve is installed after the outlet of the high-pressure cylinder and before the oxidizing gas inlet of the burner.

[0015] Furthermore, the fuel supply system includes a first high-pressure nitrogen cylinder, a fourth one-way valve, a nitrogen mass flow meter, and a high-pressure metering feeder connected in sequence. The outlet of the first high-pressure nitrogen cylinder is connected to the inlet of the nitrogen high-pressure mass flow meter, the nitrogen high-pressure mass flow meter is connected to the inlet of the high-pressure metering feeder, and the outlet of the high-pressure metering feeder is connected to the fuel inlet of the visualization reactor.

[0016] Furthermore, the flue gas cooling and exhaust system includes a flue gas cooling system and an exhaust system. The flue gas cooling system includes a nitrogen high-pressure cylinder, a fifth one-way valve, and a nitrogen high-pressure mass flow meter connected in sequence. The outlet of the nitrogen high-pressure mass flow meter is connected to the outlet pipe of the tail flue gas water-cooled dilution jacket. The exhaust system includes a first heat exchanger, a second filter, and a back pressure valve connected in sequence. The outlet of the nitrogen high-pressure cylinder is connected to the inlet of the nitrogen high-pressure mass flow meter. The outlet of the nitrogen high-pressure mass flow meter is connected to the inlet of the tail flue gas water-cooled dilution jacket of the visualization reactor. The inlet of the first heat exchanger is connected to the outlet pipe of the tail flue gas water-cooled dilution jacket of the visualization reactor. The outlet of the heat exchanger is connected to the inlet of the filter. The outlet of the filter is connected to the inlet of the back pressure valve.

[0017] Furthermore, the chiller unit provides chilled water to components in the test system that require cooling, including a water-cooled storage tank, a water-cooled dilution jacket for the tail gas of the visualization reactor, and a second heat exchanger.

[0018] Furthermore, for the visualization reactor flange burner, a coaxial burner is used if laminar combustion is being simulated, and a swirl burner is used if turbulent combustion is being simulated.

[0019] Furthermore, the middle of the flue gas water-cooled dilution jacket outlet pipe at the tail of the lower flange of the visualized reactor is a nitrogen dilution pipe. Nitrogen quenching and dilution can reduce the secondary reactions generated after fuel combustion. The nitrogen-diluted flue gas is discharged from the reactor through the channel between the dilution pipe and the water-cooled jacket.

[0020] Furthermore, the internal heating element of the visualized reactor is electrically heated. A quartz tube is arranged in the heating element to prevent direct contact between the combustion flame and the electric heating. The insulation layer is to prevent the internal temperature from being too high and affecting the pressure-bearing outer shell, and to maintain the temperature of the high-temperature zone and reduce heat dissipation.

[0021] Furthermore, the visualization reactor window uses sapphire, which can withstand high temperature and high pressure, as the observation window material. In order to protect the window from the high temperature radiation of the internal combustion flame, double-layer sapphire glass is used, with cooling water flowing through the middle layer to cool the sapphire glass.

[0022] This invention can be used not only to study the supercritical carbon dioxide combustion characteristics of solid fuels, but also the supercritical carbon dioxide combustion characteristics of gaseous and liquid fuels. Solid fuel combustion studies use solid feeders, gaseous fuel combustion studies use high-pressure gas directly, and liquid fuel combustion studies use high-pressure liquid pumps to transport fuel.

[0023] In this invention, solid fuels include pulverized coal and biomass fuels, gaseous fuels include hydrocarbon fuels such as methane and ethylene, and liquid fuels can be liquid fuels such as methanol, ethanol, and coal-water slurry.

[0024] In this invention, the high-pressure metering feeder used for solid fuel can be a combination of high-pressure gas and fluidized bed feeder. High-pressure gas carries fluidized solid particles into the burner. For gaseous and liquid fuels, a combination of high-pressure gas and flow meter is used as the metering feeder.

[0025] The water-cooled storage tank in this invention is equipped with a thermocouple for temperature measurement and a pressure gauge for pressure measurement. The side wall of the visualized reactor has lead holes for the internal electric heating wires and thermocouple wires to be led out.

[0026] In this invention, to simulate the flue gas circulation in real supercritical carbon dioxide direct combustion, a large amount of carbon dioxide is used for dilution, i.e., the carbon dioxide supply route in the experimental system, so that the proportion of carbon dioxide in the flue gas is 75-95%.

[0027] The beneficial effects of this invention are:

[0028] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0029] 1. This invention provides a visualized supercritical carbon dioxide direct combustion experimental system, comprising a visualized reactor system, a supercritical carbon dioxide supply system, an oxidant supply system, a fuel supply system, a flue gas cooling and exhaust system, and a cold water system. The high-pressure reactor provides a high-pressure reaction environment; double-layered water-cooled sapphire glass ensures safety under high-temperature and high-pressure experimental conditions.

[0030] 2. The use of a water-cooled storage tank ensured a continuous supply of carbon dioxide dilution gas during the experiment; the water-cooled dilution jacket reduced the occurrence of secondary reactions; the coaxial burner and swirl burner enabled laminar and strongly turbulent combustion experiments; the large amount of carbon dioxide dilution simulated the flue gas circulation in real supercritical carbon dioxide direct combustion, reducing the heat load in the high-pressure combustion process.

[0031] 3. The above technical solution can conduct visual combustion performance experiments of gaseous, liquid and solid fuels in a supercritical carbon dioxide environment, explore the influence of different operating parameters (such as pressure, oxygen concentration, reaction temperature, etc.) on combustion characteristics, and provide a reference for the study of supercritical carbon dioxide combustion of fuels. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the visual supercritical carbon dioxide direct combustion experimental system provided in an embodiment of the present invention;

[0033] Figure reference numerals: 11. Reactor body; 12. Coaxial burner; 13. Visualization window; 14. Tail-end flue gas water-cooled dilution jacket outlet pipe; 21. First high-pressure carbon dioxide cylinder; 22. Water-cooled storage tank; 23. First filter; 24. Liquid booster pump; 25. First check valve; 26. High-pressure carbon dioxide mass flow meter; 27. Carbon dioxide preheater; 31. High-pressure oxygen cylinder; 32. Second check valve; 33. High-pressure oxygen mass flow meter; 34. Second high-pressure carbon dioxide cylinder; 35. Third one-way valve; 36. Carbon dioxide mass flow meter; 37. Mixing tank; 38. Oxidizing gas preheater; 41. First high-pressure nitrogen cylinder; 42. Fourth one-way valve; 43. Nitrogen mass flow meter; 44. Fluidized bed high-pressure powder feeder; 51. Second high-pressure nitrogen cylinder; 52. Fifth one-way valve; 53. Nitrogen high-pressure mass flow meter; 54. First heat exchanger; 55. Second filter; 56. Back pressure valve. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Reference Figure 1 This invention provides a visual supercritical carbon dioxide direct combustion experimental system that uses pulverized coal as fuel. The system includes:

[0036] The visualization reactor system 1 includes a reactor body 11, a coaxial burner 12, a visualization window 13, and a tail gas water-cooled dilution jacket outlet pipe 14. The coaxial burner 12 is located at the upper end of the reactor body, and the tail gas water-cooled dilution jacket outlet pipe 14 is located at the lower end. The visualization window 13 is located on the reactor body 11, and the outlet flue gas is diluted and cooled by the water-cooled dilution jacket before being discharged.

[0037] The supercritical carbon dioxide supply system 2 includes a first high-pressure carbon dioxide cylinder 21, a water-cooled storage tank 22, a first filter 23, a liquid booster pump 24, a first check valve 25, a high-pressure carbon dioxide mass flow meter 26, and a carbon dioxide preheater 27. The outlet of the first high-pressure carbon dioxide cylinder is connected to the inlet of the water-cooled storage tank, the outlet of the water-cooled storage tank is connected to the first filter 23, the outlet of the first filter 23 is connected to the liquid booster pump, the outlet of the liquid booster pump is connected to the first check valve and then to the inlet of the high-pressure carbon dioxide mass flow meter, the outlet of the high-pressure carbon dioxide mass flow meter is connected to the carbon dioxide preheater, and the outlet of the carbon dioxide preheater is connected to the carbon dioxide inlet of the visualization reactor 1, for supplying supercritical carbon dioxide to the visualization reactor 1.

[0038] The oxidizing gas supply system 3 includes an oxygen supply system, a carbon dioxide supply system, and a mixing tank 37. The oxygen supply system and the carbon dioxide supply system are respectively connected to the mixing tank 37. The outlet of the mixing tank 37 is connected to an oxidizing gas preheater 38, and the outlet of the oxidizing gas preheater 38 is connected to the oxidizing gas inlet of the burner. The oxygen supply system includes an oxygen high-pressure cylinder 31, a second one-way valve 32, and an oxygen high-pressure mass flow meter 33. The carbon dioxide supply system includes a second carbon dioxide high-pressure cylinder 34, a third one-way valve 35, and a carbon dioxide mass flow meter 36. The outlet of the oxygen high-pressure cylinder 31 is connected to the second one-way valve 32 and the inlet of the oxygen high-pressure mass flow meter 33. The outlet of the second carbon dioxide high-pressure cylinder 34 is connected to the third one-way valve 35 and the inlet of the carbon dioxide mass flow meter 36. The outlets of the oxygen and carbon dioxide high-pressure mass flow meters are connected to the inlet of the mixing tank 37. The outlet of the mixing tank 37 is connected to the inlet of the oxidizing gas preheater 38, and the outlet of the oxidizing gas preheater 38 is connected to the oxidizing gas inlet of the burner.

[0039] The fuel supply system 4 uses inert gas to feed pulverized coal into the reactor. The system includes a first high-pressure nitrogen cylinder 41, a fourth one-way valve 42, a nitrogen mass flow meter 43, and a fluidized bed high-pressure feeder 44. The outlet of the high-pressure nitrogen cylinder is connected to the one-way valve and the inlet of the high-pressure nitrogen mass flow meter. The second high-pressure nitrogen mass flow meter is connected to the inlet of the fluidized bed high-pressure feeder 44. The outlet of the fluidized bed high-pressure feeder 44 is connected to the fuel inlet of the visualization reactor 1, for supplying fuel to the visualization reactor 1.

[0040] The flue gas cooling and exhaust system 5 includes a second high-pressure nitrogen cylinder 51, a fifth one-way valve 52, a high-pressure nitrogen mass flow meter 53, a first heat exchanger 54, a second filter 55, and a back pressure valve 56. The outlet of the second high-pressure nitrogen cylinder 51 is connected to the inlet of the second high-pressure nitrogen mass flow meter 53, and the outlet of the high-pressure nitrogen mass flow meter 53 is connected to the inlet of the flue gas water-cooled dilution jacket at the tail of the visualization reactor. The inlet of the first heat exchanger 54 is connected to the outlet pipe 14 of the flue gas water-cooled dilution jacket at the tail of the visualization reactor, the outlet of the heat exchanger is connected to the inlet of the filter, and the outlet of the filter is connected to the inlet of the back pressure valve. It is used to cool and exhaust the flue gas after combustion.

[0041] In this embodiment, pulverized coal is used as fuel to study the combustion characteristics of supercritical carbon dioxide. First, carbon dioxide enters a water-cooled storage tank from a high-pressure cylinder. It then undergoes high-pressure, low-temperature processing to produce liquid carbon dioxide. The liquid carbon dioxide is pressurized by a carbon dioxide liquid booster pump to above the critical pressure of carbon dioxide, passes through a carbon dioxide mass flow meter, and enters a carbon dioxide preheater. It is preheated to 600°C, becoming supercritical carbon dioxide, which then enters a visualization reactor. Oxidizing gases (oxygen and carbon dioxide) are depressurized from the high-pressure cylinder through a pressure reducing valve to the same pressure as the carbon dioxide path before entering a mass flow meter. They then enter an oxidizing gas preheater and are preheated to 350°C. The temperature is set to prevent explosions caused by excessively high oxidizing gas temperatures. The preheated, high-temperature, high-pressure oxidizing gas enters the reactor burner through a pipeline. Powdered coal from the fluidized bed high-pressure feeder is carried at room temperature by high-pressure nitrogen gas passing through a mass flow meter into the visualization reactor. A high-speed camera can be placed outside the visualization reactor to capture the combustion flame. Diluted nitrogen gas, after being depressurized by a pressure reducing valve, enters the central tube of the water-cooled dilution jacket at the tail of the visualization reactor through a mass flow meter to quench the high-temperature combustion flue gas and prevent secondary combustion reactions. The diluted nitrogen gas and combustion flue gas are then cooled by a heat exchanger and enter a filter before being discharged under reduced pressure from a back pressure valve. Therefore, the above technical solution can be used to conduct experiments on coal combustion characteristics under supercritical carbon dioxide conditions, such as ignition characteristic experiments, volatile matter and coke combustion experiments, to explore the influence of different operating parameters (e.g., pressure, oxygen concentration, reaction temperature, etc.) on combustion characteristics, measure inlet and outlet pressures, temperatures, flue gas components and coke, record flame images, and obtain flame images of the coal particle combustion process, providing a reference for the study of coal combustion under supercritical carbon dioxide conditions.

[0042] In one embodiment of the present invention, it further includes:

[0043] The cooling system, including a chiller unit, provides cooling water to the components in the test system that require cooling. It includes a water-cooled storage tank 22, a water-cooled dilution jacket outlet pipe 14 for the tail flue gas of the visualization reactor, and a first heat exchanger 54.

[0044] The data acquisition system is used to monitor and record experimental data obtained from the combustion system, as well as temperature and pressure signals in various parts of the experimental apparatus.

[0045] Specifically, the data acquisition system may include a high-definition digital camera, a high-speed video camera, a flue gas analyzer, K-type or B-type thermocouples, and a pressure sensor. During the experiment, the high-definition digital camera and high-speed video camera are used to capture images of the flame during the combustion process; the flue gas analyzer is used to monitor the composition of the flue gas online; thermocouples are used to measure the temperature at various measuring points such as the reactor wall and reactor outlet; and pressure sensors are used to monitor the pressure distribution inside the reactor, storage tank, booster pump, and pipelines. All experimental data will be recorded and stored.

[0046] In one embodiment of the present invention, it further includes:

[0047] The mixing tank 37 is connected at one end to both the oxygen supply line and the carbon dioxide supply line, and at the other end to the oxidizing gas inlet of the coaxial burner. In this embodiment, by setting up the mixing tank 37, the effect of the baffles inside the mixing tank can be used to improve the uniformity of gas mixing.

[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A visual supercritical carbon dioxide direct combustion experimental system, characterized in that, Using pulverized coal as fuel, the system includes a visual reactor system, a supercritical carbon dioxide supply system, an oxidant supply system, a fuel supply system, and a flue gas cooling and exhaust system. The fuel supply system includes a first high-pressure nitrogen cylinder, a high-pressure nitrogen mass flow meter, and a high-pressure metering feeder connected in sequence. The outlet of the first high-pressure nitrogen cylinder is connected to the inlet of the high-pressure nitrogen mass flow meter, the high-pressure nitrogen mass flow meter is connected to the inlet of the high-pressure metering feeder, and the outlet of the high-pressure metering feeder is connected to the fuel inlet of the burner. The visualization reactor system includes a reactor body, a supercritical carbon dioxide burner, a visualization window, and a tail flue gas water-cooled dilution jacket outlet pipe. The supercritical carbon dioxide burner is located at the upper end of the reactor body, the visualization window is located on the reactor body, and the tail flue gas water-cooled dilution jacket outlet pipe is located at the lower end of the reactor body. The outlet flue gas is discharged after being diluted and cooled by the water-cooled dilution jacket. The supercritical carbon dioxide supply system is connected to the supercritical carbon dioxide burner in the visualized reactor and is used to supply supercritical carbon dioxide to the supercritical carbon dioxide burner. The oxidant supply system is connected to the supercritical carbon dioxide burner in the visualization reactor and is used to supply oxidant to the supercritical carbon dioxide burner. The fuel supply system is connected to a supercritical carbon dioxide burner in the visualized reactor and is used to supply fuel to the supercritical carbon dioxide burner. The flue gas cooling and discharge system is connected to the tail flue gas water-cooled dilution jacket outlet pipe in the visualized reactor and is used to treat the flue gas discharged from the reactor body.

2. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The burners in the visualized reactor are either coaxial burners that simulate near-laminar flow or swirling burners that simulate strong turbulent mixing.

3. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The supercritical carbon dioxide supply system includes a first high-pressure carbon dioxide cylinder, a water-cooled storage tank, a first filter, a liquid booster pump, a high-pressure carbon dioxide mass flow meter, and a carbon dioxide preheater connected in sequence. The outlet of the carbon dioxide preheater is connected to the visualization reactor system.

4. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The oxidizing gas supply system includes an oxygen supply system and a carbon dioxide supply system, which are respectively connected to a mixing tank. The outlet of the mixing tank is connected to an oxidizing gas preheater, and the outlet of the oxidizing gas preheater is connected to the oxidizing gas inlet of the burner. The oxygen supply system includes a high-pressure oxygen cylinder and an oxygen high-pressure mass flow meter connected in sequence, wherein the oxygen high-pressure mass flow meter is connected to the mixing tank. The carbon dioxide supply system includes a second high-pressure carbon dioxide cylinder and a carbon dioxide mass flow meter connected in sequence, wherein the carbon dioxide mass flow meter is connected to the mixing tank.

5. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The flue gas cooling and exhaust system includes a flue gas cooling system and an exhaust system. The flue gas cooling system includes a nitrogen high-pressure cylinder and a nitrogen high-pressure mass flow meter connected in sequence. The outlet of the nitrogen high-pressure mass flow meter is connected to the outlet pipe of the tail flue gas water-cooled dilution jacket. The exhaust system includes a first heat exchanger, a second filter, and a back pressure valve connected in sequence. The inlet of the first heat exchanger is connected to the outlet pipe of the tail flue gas water-cooled dilution jacket.

6. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: It includes a chiller unit for providing chilled water to components in the experimental system that require cooling, including a water-cooled storage tank, a water-cooled dilution jacket for the tail gas of the visualization reactor, and a second heat exchanger.

7. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The reactor body is divided into an outer pressure-bearing shell, an inner heating element, and an insulation layer. Visual viewing windows for observing combustion characteristics are opened on the reactor body wall and the insulation layer.

8. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The outlet pipe of the water-cooled dilution jacket at the tail of the visible reactor is a nitrogen dilution pipe in the middle. The nitrogen-diluted flue gas is discharged from the reactor through the channel between the dilution pipe and the water-cooled jacket.

9. The visual supercritical carbon dioxide direct combustion experimental system as described in claim 1, characterized in that: The visualization reactor window uses sapphire, which can withstand high temperature and high pressure, as the observation window material. It uses double-layered sapphire glass with cooling water in the middle layer.

Images