Series cascade multiple oxidation and heat exchange system and operation method of supercritical water system

Abstract

A series cascade multiple oxidation and heat exchange system and an operating method for a supercritical water system, wherein a primary gasification reactor, a primary oxidation chamber, a primary heat exchanger, a secondary gasification reactor, a secondary oxidation chamber, a secondary heat exchanger, a tertiary oxidation chamber, a tertiary heat exchanger, and a gas-liquid separation device are connected in sequence; the primary oxidation chamber, the secondary oxidation chamber, and the tertiary oxidation chamber are all connected to an oxidant supply module; the primary gasification reactor and the secondary gasification reactor are connected to a raw material supply module; one end of the water supply module is connected to the raw material supply module, and the other end is connected to the liquid end of the gas-liquid separation device, and a high-pressure product gas storage tank is connected to the gas end of the gas-liquid separation device. The present invention proposes a series cascade multiple oxidation and heat exchange system and an operating method for a supercritical water system, which can improve the production efficiency of the supercritical water gasification system, reduce the heat transfer demand, and reduce the reactor temperature through cascade multiple oxidation, and improve the heat transfer efficiency in combination with the comprehensive design of the multi-stage heat exchanger.

Description

Technical Field

[0001] The present invention belongs to the fields of clean energy conversion and coal chemical industry, and particularly relates to a series cascade multiple oxidation and heat exchange system of a supercritical water system and an operating method. Background Art

[0002] Hydrogen production from organic waste, biomass, and coal gasification is a key future hydrogen source and power generation strategy. Supercritical technology offers significant advantages in achieving this goal. Supercritical water possesses unique physical and chemical properties, such as weak hydrogen bonds, low polarity, a high diffusion coefficient, and the ability to dissolve most organic matter and gases. These properties enable reactions to proceed in a homogeneous phase, significantly accelerating the reaction rate. Supercritical water gasification and oxidation reactions operate at low temperatures and do not produce traditional pollutants, making them a promising clean technology.

[0003] Since supercritical water gasification technology has so many advantages in treating and utilizing organic matter such as biomass waste, many scholars at home and abroad have conducted extensive research on it after it was proposed in the 1970s, and have made many progress and achievements. Professor Andrea Kruse of Germany pointed out in a review paper on Supercritical water gasification that there are still technical difficulties such as optimizing gas production at high concentrations, achieving high energy recovery self-heating in engineering, and system instability.

[0004] Currently, the supercritical water gasification process faces the following urgent challenges: heat transfer in high-pressure, high-temperature systems is limited by material costs and wall thickness, necessitating process optimization to minimize heat transfer while simultaneously improving the efficiency of existing heat exchangers. The heat source required for supercritical water gasification is generated through mild oxidation, which avoids the pollution associated with combustion heating. Heat transfer can be achieved with only a small pressure differential between the hot and cold heat exchange fluids, reducing the thickness of the heat exchanger pipes. However, the material temperature limit at supercritical pressure is significant, and with oxidation temperatures limited, process optimization and technological breakthroughs are required to achieve self-heating in the system. Summary of the Invention

[0005] The object of the present invention is to provide a series cascade multiple oxidation and heat exchange system and an operating method for a supercritical water system to solve the problems of large material temperature restrictions under supercritical pressure, limited oxidation temperature, and difficulty in self-heating of the system.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A series cascade multiple oxidation and heat exchange system for a supercritical water system comprises a primary gasification reactor, a primary oxidation chamber, a primary heat exchanger, a secondary gasification reactor, a secondary oxidation chamber, a secondary heat exchanger, a tertiary oxidation chamber, a tertiary heat exchanger, a gas-liquid separation device, an oxidant supply module, a raw material supply module, a water supply module and a high-pressure product gas storage tank; the primary gasification reactor, the primary oxidation chamber, the primary heat exchanger, the secondary gasification reactor, the secondary oxidation chamber, the secondary heat exchanger, the tertiary oxidation chamber, the tertiary heat exchanger and the gas-liquid separation device are connected in sequence; the primary oxidation chamber, the secondary oxidation chamber and the tertiary oxidation chamber are all connected to the oxidant supply module; the primary gasification reactor and the secondary gasification reactor are connected to the raw material supply module; one end of the water supply module is connected to the raw material supply module, and the other end is connected to the liquid end of the gas-liquid separation device, and the high-pressure product gas storage tank is connected to the gas end of the gas-liquid separation device.

[0008] Furthermore, the liquid end of the gas-liquid separation device is also connected to a high-pressure water pressurizing device, which is sequentially connected to the third-stage heat exchanger, the second-stage heat exchanger and the first-stage heat exchanger.

[0009] Furthermore, the water outlet end of the first-stage heat exchanger is connected to the first-stage gasification reactor.

[0010] Furthermore, the water supply module is a high-pressure water storage tank, and a waste heat exchange device and a pressure control device are sequentially arranged between the gas-liquid separation device and the water supply module.

[0011] Furthermore, the raw material supply module includes a high-pressure raw material storage tank and a gasification raw material pressurizing device. The high-pressure raw material storage tank is connected to the gasification raw material pressurizing device, and the gasification raw material pressurizing device is connected to a waste heat heat exchange device. The waste heat exchange device here is divided into two routes and is respectively connected to the first-level gasification reactor and the second-level gasification reactor.

[0012] Furthermore, the inlet of the high-pressure raw material storage tank is connected to the outlet of the high-pressure water storage tank.

[0013] Furthermore, a waste heat exchange device and a pressure control device are provided between the inlet of the high-pressure product gas storage tank and the gas-liquid separation device; the outlet of the high-pressure product gas storage tank is connected to the pressure control device and the waste heat exchange device in sequence, and the waste heat exchange device here is divided into two routes and connected to the primary gasification reactor and the secondary gasification reactor respectively.

[0014] Furthermore, the oxidant supply module includes a high-pressure oxidant storage tank and an oxidant pressurizing device. The outlet of the high-pressure oxidant storage tank is connected to the oxidant pressurizing device, and the oxidant pressurizing device is connected to a waste heat exchange device. The waste heat exchange device here is divided into three routes and is respectively connected to the primary oxidation chamber, the secondary oxidation chamber and the tertiary oxidation chamber.

[0015] Furthermore, the waste heat exchange device uses the waste heat through the circulating water pipeline to preheat the reactants entering the reactor.

[0016] Furthermore, the operation method of the series-connected cascade multiple oxidation and heat exchange system of the supercritical water system comprises the following steps:

[0017] Two-stage coal gasification reaction: After the startup conditions are met, the raw materials in the high-pressure raw material storage tank are pressurized by the gasification raw material pressurizing device and controlled by valves, and then input into the primary gasification reactor and the secondary gasification reactor. At the same time, the high-pressure product gas storage tank inputs high-pressure gas for raw material injection. Under the action of high-temperature supercritical water, the gasification reaction occurs;

[0018] Oxidation reaction of coal gasification products: The products of the primary gasification reactor enter the primary oxidation chamber, and the products of the secondary gasification reactor enter the secondary oxidation chamber. At the same time, the oxidant in the high-pressure oxidant storage tank is input into the oxidation chamber through the oxidant pressurizing device, and a partial oxidation exothermic reaction occurs with the gasification products. The primary and secondary gasification reactors are in a series relationship in terms of process flow. The primary gasification reactor uses high-temperature supercritical water generated by heat exchange as the gasification medium. After the products are partially oxidized and heated in the primary oxidation chamber, they enter the secondary gasification reactor and are directly used as the gasification medium for the gasification reaction.

[0019] Cascade multiple oxidation process: Partial oxidation occurs in the primary oxidation chamber, and the heat released is mainly used to form a high-temperature gasification medium to supply the secondary gasification reactor. The secondary and tertiary oxidation chambers also undergo partial oxidation to release heat, which is transferred to high-pressure water through the secondary and tertiary heat exchangers to generate supercritical water for supplying the primary gasification reactor. The secondary and tertiary oxidation chambers are used for staged oxidation heat release.

[0020] Heat exchange: The primary, secondary and tertiary heat exchangers are combined for heat exchange. The waste heat exchange device utilizes the waste heat through the circulating water pipeline. The raw materials, oxidants and product gases used for pneumatic atomization heated by the waste heat are preheated and then enter the reactor;

[0021] High-temperature gas-liquid separation and high-temperature water circulation: The system's gas-liquid separation device is arranged before the pressure control device and the waste heat exchange device, and medium and low-temperature liquid water is directly recycled through the high-pressure water pressurization device.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] The present invention proposes a series cascade multiple oxidation and heat exchange system and operation method for a supercritical water system, which can improve the production efficiency of the supercritical water gasification system, reduce the heat transfer demand, and lower the reactor temperature through cascade multiple oxidation. The comprehensive design of the multi-stage heat exchanger is combined to improve the heat transfer efficiency.

[0024] First, the first-stage gasification reactor uses high-temperature supercritical water generated by heat exchange as the gasification medium. After its product is partially oxidized and heated in the first-stage oxidation chamber, it enters the second-stage gasification reactor and is directly used as the gasification medium for the gasification reaction. This series process design can greatly reduce the amount of high-temperature gasification medium generated by heat exchange, reduce the heat exchange process of the system, and thus improve production efficiency.

[0025] Second, the use of secondary and tertiary oxidation chambers for staged oxidation and heat release results in a milder reaction temperature, which can avoid damage to the heat exchange tubes caused by excessively high temperatures during the oxidation process, reduce the cost of high-quality materials, and also reduce the oxygen consumption of the system.

[0026] Third, preheating the raw materials and oxidant allows them to enter the reactor at a higher temperature, which can reduce the amount and temperature of the high-temperature gasification medium, help reduce the cold and hot mixing losses in the reactor, improve the reactor efficiency, and achieve an overall energy efficiency improvement of the system.

[0027] Fourth, directly performing gas-liquid separation on high-pressure and incompletely cooled fluids can avoid heat loss from two heat exchanges of first cooling and then heating, and also avoid a large amount of pressure loss from first reducing the pressure and then increasing the pressure; at the same time, cooling and regulating the pressure after the product gas is separated can avoid unstable system pressure fluctuations caused by cooling and pressure regulation of gas-liquid mixing, thereby improving system efficiency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the principle of the present invention;

[0029] Among them, 1-first-stage gasification reactor, 2-second-stage gasification reactor, 3-first-stage oxidation chamber, 4-second-stage oxidation chamber, 5-third-stage oxidation chamber, 6-first-stage heat exchanger, 7-second-stage heat exchanger, 8-third-stage heat exchanger, 9-gas-liquid separation device, 10-pressure control device, 11-high-pressure water pressurizing device, 12-oxidant pressurizing device, 13-gasification raw material pressurizing device, 14-waste heat exchange device, 15-high-pressure oxidant storage tank, 16-high-pressure raw material storage tank, 17-high-pressure water storage tank and 18-high-pressure product gas storage tank. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0031] The accompanying drawings show schematic diagrams of principles according to embodiments disclosed herein.

[0032] The present invention relates to a comprehensive design of a series cascade multiple oxidation of a supercritical water system, which belongs to the category of supercritical water gasification systems. The characteristics of the design are that it uses a multi-stage large-space oxidation chamber for oxidation as a heat source, separates the oxidation process from the heat exchange process, can avoid damage to the heat exchange tubes during the oxidation process, reduce the cost of high-quality materials, reduce the oxygen consumption of the system, and uses a multi-stage heat exchanger to preheat the supercritical water, raw materials and oxidant. The multi-stage heat exchanger is used to achieve a cascade transfer of heat. In addition, in order to avoid the high temperature generated by the one-time complete oxidation process and the problem that the one-time gasification production efficiency needs to be improved, after theoretical calculation, a multi-stage gasification reactor series system is proposed, which can not only reduce the size of the gasification reactor, but also make full use of the gasification medium, improve the production efficiency of the gasification device, and improve the efficiency of the overall process.

[0033] See also Figure 1 As shown, the present invention is a series cascade multiple oxidation and heat exchange system and operation method of a supercritical water system, including a primary gasification reactor 1, a secondary gasification reactor 2, a primary oxidation chamber 3, a secondary oxidation chamber 4, a tertiary oxidation chamber 5, a primary heat exchanger 6, a secondary heat exchanger 7, a tertiary heat exchanger 8, a gas-liquid separation device 9, a pressure control device 10, a high-pressure water pressurizing device 11, an oxidant pressurizing device 12, a gasification raw material pressurizing device 13, a waste heat heat exchange device 14, a high-pressure oxidant storage tank 15, a high-pressure raw material storage tank 16, a high-pressure water storage tank 17 and a high-pressure product gas storage tank 18.

[0034] Among them, the gasified raw materials flow through the primary gasification reactor 1, the primary oxidation chamber 3, the primary heat exchanger 6, the secondary gasification reactor 2, the secondary oxidation chamber 4, the secondary heat exchanger 7, the tertiary oxidation chamber 5, and the tertiary heat exchanger 8 in sequence, react or heat exchange, and finally enter the gas-liquid separation device 9 and the pressure control device 10 to become product gas.

[0035] The series connection refers to the sequential connection of the primary gasification reactor 1, the primary oxidation chamber 3, the secondary gasification reactor 2, the secondary oxidation chamber 4, and the tertiary oxidation chamber 5 in the reaction flow. The gasification product of the primary gasification reactor 1 is used as a reactant in the primary oxidation chamber 3, and undergoes an oxidation reaction with the oxidant input into the secondary oxidation chamber 3 to release heat. The high-temperature product of the primary oxidation chamber 3 is then used as a gasification medium in the secondary gasification reactor 2. The gasification product of the secondary gasification reactor 2 then serves as an oxidation reactant in the secondary oxidation chamber 4 and the tertiary oxidation chamber 5, and undergoes another oxidation reaction with the input oxidant to produce a high-temperature fluid.

[0036] The cascade multiple oxidation means that the three oxidation chambers, the primary oxidation chamber 3, the secondary oxidation chamber 4 and the tertiary oxidation chamber 5, react in sequence, and the oxidant is input into each oxidation chamber through the oxidant pressurizing device 12, and multiple partial oxidations are performed to gradually generate heat.

[0037] The integrated heat exchange design involves the placement of a primary heat exchanger 6, a secondary heat exchanger 7, and a tertiary heat exchanger 8 between the reactors. Furthermore, a waste heat exchanger 14 is included to preheat the feedstock, oxidant, and product gas used for pneumatic atomization, via a circulating water pipeline.

[0038] The high-pressure water pressurizing device 11, the oxidant pressurizing device 12 and the gasification raw material pressurizing device 13 transport fluids to each reactor and heat exchanger through pipelines to meet the reaction and heat exchange needs. During this process, the flow rate is controlled and distributed through valves and automatic control systems, and at the same time, the pressure inside the high-pressure oxidant storage tank 15, the high-pressure raw material storage tank 16, the high-pressure water storage tank 17 and the high-pressure product gas storage tank 18 is guaranteed to be stable.

[0039] The high-temperature gas-liquid separation and high-temperature water circulation design mentioned above means that the three-stage heat exchanger 8 is directly connected to the gas-liquid separation device 9, that is, the gas-liquid separation device 9 is arranged before the pressure control device 10 and the waste heat exchange device 14. This reduces unnecessary heat transfer and pressure changes.

[0040] The operation steps of the series cascade multiple oxidation and heat exchange system of the supercritical water system are as follows:

[0041] a. Gasification Material Transportation: High-pressure water storage tank 17 provides raw water to high-pressure raw material storage tank 16 for producing high-pressure slurry. After being pressurized by gasification raw material pressurization device 13, the high-pressure slurry enters waste heat exchange device 14 for preheating. The flow rate is then distributed through a valve block and control system to enter primary gasification reactor 1 and secondary gasification reactor 2, respectively. Simultaneously, to ensure smooth injection of the high-pressure slurry into the gasification reactors, pneumatic atomization is performed using preheated gas from high-pressure product gas storage tank 18. Auxiliary gas undergoes a similar pressurization and preheating process.

[0042] b Two-stage coal gasification reaction: The slurry entering the primary gasification reactor 1 undergoes a primary coal gasification reaction with the supercritical water from the primary heat exchanger 6, and the slurry entering the secondary gasification reactor 2 undergoes a primary coal gasification reaction with the supercritical high-temperature fluid after heat exchange from the primary heat exchanger 6. Since the supercritical high-temperature fluid after heat exchange from the primary heat exchanger 6 contains a large amount of water, the water is fully used as the gasification medium through the secondary gasification reactor 2, which can improve production efficiency.

[0043] c. Cascade multiple oxidation process: the oxidant in the high-pressure oxidant storage tank 15 is pressurized by the oxidant pressurizing device 12, and the pressurized oxidant is preheated by the waste heat heat exchange device 14. Then, the flow is distributed through the valve group and the control system to enter the oxidizers of each stage respectively. First, in the primary oxidation chamber 3, the oxidant reacts with the gasification gas from the primary gasification reactor 1, with the purpose of releasing heat to increase the fluid temperature. After entering the primary heat exchanger 6 for temperature adjustment, it enters the secondary gasification reactor 2 and is used as a high-temperature gasification medium, and heats high-pressure water to be used as the gasification medium of the primary gasification reactor 1; then, in the secondary oxidation chamber 4, the oxidant reacts with the gas from the secondary gasification reactor 2, with the purpose of partially releasing heat to increase the fluid temperature, and enters the secondary heat exchanger 7 to heat the high-pressure water. Finally, in the tertiary oxidation chamber 5, the oxidant reacts again with the reaction fluid cooled by the secondary heat exchanger 7, raising the fluid temperature, and enters the tertiary heat exchanger 8, which is also used to heat the high-pressure water. The design of two and three stages of oxidation can avoid the limitations brought by the pinch point, reduce the maximum temperature of the reactor, reduce material costs, and improve heat transfer efficiency.

[0044] d. Comprehensive heat exchange design: In addition to the three-stage heat exchange design adopted in the cascade multiple oxidation process, the heat exchange process also includes the utilization of waste heat. After gas-liquid separation, in the waste heat heat exchange device 14, circulating water is used to exchange heat with the gas and liquid water containing waste heat respectively. The medium-temperature circulating water formed is used to preheat the gasification raw materials, oxidants and high-pressure product gases for auxiliary injection.

[0045] e High-temperature gas-liquid separation and high-temperature water circulation design: The high-pressure fluid containing waste heat after the reaction and three-stage heat exchange is subjected to gas-liquid separation. A portion of the liquid water containing waste heat is directly recycled using the high-pressure water pressurizing device 11, and the excess water enters the waste heat heat exchange device 14. The product gas containing waste heat is cooled by the waste heat heat exchange device 14 and then pressurized and stored.

[0046] f End the reaction process: After the gasification reaction is completed, first close the gasification raw material pressurizing device 13 and the oxidant pressurizing device 12, stop inputting raw materials and oxidants, and after the system has been running continuously for one hour, close the high-pressure water pressurizing device 11. After the system has slowly cooled down, close the pressure control device 10, and there will be no flow at all inlets and outlets.

[0047] The series-connected cascade multiple oxidation and heat exchange system of the supercritical water system proposed in the present invention is characterized in that two-stage gasification reactors are connected in series, which fully utilizes the high-temperature gasification medium and improves production efficiency; the reaction temperature is lowered and the heat exchange efficiency is improved by combining multiple oxidation with heat exchange preheating design; and the high-pressure water with waste heat is directly pressurized and circulated through high-pressure separation to avoid pressure loss, reduce pump work, and improve efficiency and stability.

[0048] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A series cascade multiple oxidation and heat exchange system of a supercritical water system, characterized in that: The invention comprises a first-stage gasification reactor (1), a first-stage oxidation chamber (3), a first-stage heat exchanger (6), a second-stage gasification reactor (2), a second-stage oxidation chamber (4), a second-stage heat exchanger (7), a third-stage oxidation chamber (5), a third-stage heat exchanger (8), a gas-liquid separation device (9), an oxidant supply module, a raw material supply module, a water supply module and a high-pressure product gas storage tank (18); the first-stage gasification reactor (1), the first-stage oxidation chamber (3), the first-stage heat exchanger (6), the second-stage gasification reactor (2), the second-stage oxidation chamber (4), the second-stage heat exchanger (7), the third-stage oxidation chamber (5), the third-stage heat exchanger (8) and the gas-liquid separation device (9) are connected in sequence; the first-stage oxidation chamber (3), the second-stage oxidation chamber (4) and the third-stage oxidation chamber (5) are all connected to the oxidant supply module; the first-stage gasification reactor (1) and the second-stage gasification reactor (2) are connected to the raw material supply module; one end of the water supply module is connected to the raw material supply module, and the other end is connected to the liquid end of the gas-liquid separation device (9); the high-pressure product gas storage tank (18) is connected to the gas end of the gas-liquid separation device (9); The liquid end of the gas-liquid separation device (9) is also connected to a high-pressure water pressurizing device (11), and the high-pressure water pressurizing device (11) is sequentially connected to the third-stage heat exchanger (8), the second-stage heat exchanger (7) and the first-stage heat exchanger (6); The water outlet end of the first-stage heat exchanger (6) is connected to the first-stage gasification reactor (1).

2. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 1 is characterized in that: The water supply module is a high-pressure water storage tank (17), and a waste heat exchange device (14) and a pressure control device (10) are sequentially arranged between the gas-liquid separation device (9) and the water supply module.

3. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 2, characterized in that: The raw material supply module includes a high-pressure raw material storage tank (16) and a gasification raw material pressurizing device (13). The high-pressure raw material storage tank (16) is connected to the gasification raw material pressurizing device (13). The gasification raw material pressurizing device (13) is connected to a waste heat heat exchange device (14). The waste heat exchange device (14) is divided into two paths and connected to the first-stage gasification reactor (1) and the second-stage gasification reactor (2).

4. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 3, characterized in that: The inlet of the high-pressure raw material storage tank (16) is connected to the outlet of the high-pressure water storage tank (17).

5. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 1, characterized in that: A waste heat exchange device (14) and a pressure control device (10) are provided between the inlet of the high-pressure product gas storage tank (18) and the gas-liquid separation device (9); the outlet of the high-pressure product gas storage tank (18) is connected to the pressure control device (10) and the waste heat exchange device (14) in sequence, wherein the waste heat exchange device (14) is divided into two paths and connected to the primary gasification reactor (1) and the secondary gasification reactor (2) respectively.

6. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 1, characterized in that: The oxidant supply module includes a high-pressure oxidant storage tank (15) and an oxidant pressurizing device (12). The outlet of the high-pressure oxidant storage tank (15) is connected to the oxidant pressurizing device (12). The oxidant pressurizing device (12) is connected to a waste heat exchange device (14). The waste heat exchange device (14) is divided into three paths and respectively connected to the primary oxidation chamber (3), the secondary oxidation chamber (4) and the tertiary oxidation chamber (5).

7. The series cascade multiple oxidation and heat exchange system of the supercritical water system according to claim 1, characterized in that: The waste heat exchange device (14) uses the waste heat to preheat the reactants entering the reactor through the circulating water pipeline.

8. The method for operating a series cascade multiple oxidation and heat exchange system of a supercritical water system is characterized in that: The series cascade multiple oxidation and heat exchange system of the supercritical water system according to any one of claims 1 to 7 comprises the following steps: Two-stage coal gasification reaction: After reaching the start-up conditions, the raw materials in the high-pressure raw material storage tank (16) are pressurized by the gasification raw material pressurizing device (13) and controlled by valves, and are input into the first-stage gasification reactor (1) and the second-stage gasification reactor (2). At the same time, the high-pressure product gas storage tank (18) inputs high-pressure gas for the injection of the raw materials. Under the action of high-temperature supercritical water, a gasification reaction occurs; Oxidation reaction of coal gasification products: the products of the primary gasification reactor (1) enter the primary oxidation chamber (3), and the products of the secondary gasification reactor (2) enter the secondary oxidation chamber (4). At the same time, the oxidant in the high-pressure oxidant storage tank (15) is input into the oxidation chamber through the oxidant pressurizing device (12), and a partial oxidation exothermic reaction occurs with the gasification products. The primary gasification reactor (1) and the secondary gasification reactor (2) are in a series relationship in terms of the process flow. The primary gasification reactor (1) uses high-temperature supercritical water generated by heat exchange as the gasification medium. After the products are partially oxidized and heated in the primary oxidation chamber (3), they enter the secondary gasification reactor (2) and are directly used as the gasification medium for the gasification reaction. Cascade multiple oxidation process: Partial oxidation occurs in the primary oxidation chamber (3), and the heat released is mainly used to form a high-temperature gasification medium to supply the secondary gasification reactor (2). The secondary oxidation chamber (4) and the tertiary oxidation chamber (5) also undergo partial oxidation to release heat, and the heat is transferred to high-pressure water through the secondary heat exchanger (7) and the tertiary heat exchanger (8) to generate supercritical water for supplying the primary gasification reactor (1); the secondary oxidation chamber (4) and the tertiary oxidation chamber (5) are used to perform oxidation heat release in stages; Heat exchange: The primary heat exchanger (6), the secondary heat exchanger (7), and the tertiary heat exchanger (8) are combined for heat exchange, and the waste heat heat exchange device (14) utilizes the waste heat through the circulating water pipeline. The raw materials, oxidants, and product gases used for pneumatic atomization heated by the waste heat are preheated and then enter the reactor; High-temperature gas-liquid separation and high-temperature water circulation: The gas-liquid separation device (9) of the system is arranged before the pressure control device (10) and the waste heat exchange device (14), and the medium and low-temperature liquid water is directly recycled through the high-pressure water pressurizing device (11).

Images