Supercritical continuous oxidation system for high-salinity and high-concentration organic wastewater

Abstract

The invention belongs to the field of supercritical water oxidation, and provides a high-salinity high-concentration organic wastewater supercritical continuous oxidation system which comprises a feeding system, a reaction system, a salt discharging system, a cooling system and a control system. The material and an oxidant are pressurized, mixed and preheated and then enter a reaction system for reaction; a high-temperature product generated by reaction enters a cold water tank to be cooled after waste heat recovery; subcritical water is introduced into the subcritical saline water tank, precipitated salt enters the saline water flash tank in the form of subcritical saline water, solid salt is obtained, and flash high-temperature gas enters the cooling system to be cooled. Compared with other existing systems, the feeding system is prevented from being blocked by controlling the feeding preheating temperature and arranging the air pulse purge valve; by arranging the subcritical saline water tank and the saline water flash tank, continuous salt discharging of the system and blockage prevention of the discharging system are achieved, and meanwhile the temperature and pressure bearing requirements of a salt discharging valve and generation of strong saline water are greatly reduced; by adopting the carbon steel pressure-bearing wall lined with the nickel-based alloy, the corrosion prevention and cost reduction of the reactor are realized, and the electromagnetic heating efficiency is greatly improved. The method has wide popularization and application prospects.

Description

Technical Field

[0001] The invention relates to the field of high-salt and high-concentration organic wastewater treatment, and in particular to a high-salt and high-concentration organic wastewater supercritical continuous oxidation system. Background Art

[0002] Supercritical water oxidation technology (SCWO) is a green and efficient advanced oxidation treatment technology. Compared with traditional treatment methods, supercritical water oxidation technology has the advantages of high efficiency, thorough reaction, and pollution-free products. However, the three major problems of blockage, corrosion, and high cost have always restricted the development and industrialization of this technology. Especially for the treatment of high-salt and high-concentration organic wastewater, how to smoothly and effectively solve the blockage and salt discharge problems is a problem that needs to be solved urgently.

[0003] The Chinese invention patent with the patent number CN202410714380 discloses "a supercritical water oxidation system for continuous salt slag discharge" and proposes an anti-clogging method to control the material preheating temperature below 360°C, but salt precipitation and organic coking will still occur at this temperature; at the same time, the patent proposes a salt discharge method that uses normal temperature oxygen to pressurize and cool the salt discharge buffer tank, which can easily cause scratches and leaks on the high-temperature salt discharge valve. The Chinese invention patent with the patent number CN202111580643 discloses "a supercritical water oxidation industrial salt discharge method and system" and proposes an intermittent salt discharge method in which the salt discharge buffer tank is alternately charged and released, but the high-temperature salt discharge valve of the system has a set pressure difference that is too small, which can easily cause the precipitated salt to stick to the wall and the salt discharge valve to be blocked.

[0004] The Chinese utility model patent with patent number CN201621164542 proposes a carbon steel, stainless steel and nickel-based alloy lined titanium pressure wall. However, actual application found that the corrosion resistance of titanium alloy in the supercritical oxidation system of high-salt and high-concentration organic wastewater is not as good as that of nickel-based alloy. At the same time, when the pressure wall is made of stainless steel and nickel-based alloy, the electromagnetic heating efficiency is greatly reduced. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a supercritical continuous oxidation system for high-salt and high-concentration organic wastewater.

[0006] The technical solution of the present invention:

[0007] A supercritical continuous oxidation system for high-salt and high-concentration organic wastewater, comprising a feeding system, a reaction system, a salt removal system, a cooling system and a control system;

[0008] The feeding system is composed of a clean water tank, a clean water valve, a sewage tank, a sewage valve, a high-pressure feeding pump, an air compressor, a buffer tank, an air flow regulating valve, an air flow meter, an air pulse purge valve, a jet mixer, a waste heat preheater, an electromagnetic preheater and connecting pipelines.

[0009] The clean water tank and the clean water valve are connected in series to form a clean water pipeline, the sewage tank and the sewage valve are connected in series to form a sewage pipeline, the clean water pipeline and the sewage pipeline are connected in parallel to the inlet of the high-pressure feed pump, the air compressor, the buffer tank, the air flow regulating valve, and the air flow meter are connected in series in sequence through pipelines to form an air intake pipeline, the air pulse purge valve, the air flow regulating valve, and the air flow meter are connected in parallel to form a pulse purge pipeline, the liquid inlet of the jet mixer is connected to the outlet of the high-pressure feed pump through a pipeline, the gas inlet is connected to the outlet of the air flow meter and the outlet of the air pulse purge valve through pipelines, the outlet of the jet mixer is connected to the inlet of the waste heat preheater through a pipeline, the outlet of the waste heat preheater is connected to the inlet of the electromagnetic preheater, and the outlet of the electromagnetic preheater is connected to the feed port of the reaction system through a pipeline;

[0010] The reaction system is composed of an upper end cover, an inner cylinder, a temperature measuring sleeve, a conical guide plate, an outer cylinder, a C-type sealing ring, an insulation layer, an electromagnetic heating coil, a bursting disc, a high-temperature fluid electric regulating outlet valve and connecting pipelines.

[0011] The upper end cover is provided with a feed port, a temperature measuring port and a pressure relief port, and the feed port is located at the center of the upper end cover, the upper end of the inner tube is coaxially fixed to the upper end cover with the feed port, and the temperature measuring port and the pressure relief port are located inside the inner tube, the upper end of the temperature measuring sleeve is welded to the upper end cover through the temperature measuring port, and the lower end penetrates into the middle of the inner tube, a conical guide plate is installed at the lower end of the inner tube, a salt discharge port is provided at the lower end of the outer tube, a high-temperature fluid outlet is provided at the upper part of the side wall of the outer tube, the outer tube is composed of an anti-corrosion lining layer and a pressure-bearing wall, a C-type sealing ring is installed between the upper end cover and the outer tube, and they are connected by bolts; the insulator The heat layer is coated on the outside of the outer cylinder, the electromagnetic heating coil is wound outside the insulation layer, the bursting disc is installed at the pressure relief port of the upper end cover, the high-temperature fluid outlet is connected to the tube side inlet of the shell-and-tube heat exchanger through a pipeline, the shell-and-tube heat exchanger outlet is connected to the shell side inlet of the waste heat preheater through a pipeline, the shell side outlet of the waste heat preheater is connected to the inlet of the high-temperature fluid electric regulating outlet valve through a pipeline, the outlet of the high-temperature fluid electric regulating outlet valve is connected to the high-temperature fluid inlet of the cooling tower of the cooling system through a pipeline, and the salt discharge port is connected to the high-temperature salt discharge valve inlet of the salt discharge system;

[0012] The salt discharge system is composed of a high-temperature salt discharge valve, a subcritical brine tank, a low-temperature salt discharge valve, a brine flash tank, a cold water plunger pump, a casing heat exchanger, an automatic pressure regulating valve and connecting pipelines.

[0013] The high-temperature salt discharge valve, the subcritical brine tank, and the low-temperature salt discharge valve are connected in sequence from top to bottom. A subcritical brine inlet is provided at the middle and upper part of the side wall of the brine flash tank, a solid salt outlet is provided at the bottom, and a flash gas outlet is provided at the top. A flash defoaming layer is provided inside the brine flash tank between the subcritical brine inlet and the flash gas outlet. The inlet of the cold water plunger pump is connected to the cooling water tower of the cooling system through a pipeline, and the outlet of the cold water plunger pump is connected to the shell inlet of the shell-and-tube heat exchanger through a pipeline. The shell-and-tube heat exchanger shell outlet is respectively connected to the subcritical water inlet of the side wall of the subcritical brine tank and the inlet of the automatic pressure regulating valve through a pipeline, and the outlet of the automatic pressure regulating valve is connected to the cooling water inlet of the cooling tower of the cooling system through a pipeline, and the outlet of the low-temperature salt discharge valve is connected to the subcritical brine inlet of the brine flash tank through a pipeline, and the flash gas outlet of the brine flash tank is connected to the high-temperature fluid inlet of the cooling tower of the cooling system through a pipeline:

[0014] The cooling system consists of a cooling tower, a cooling water tower, a fan, a circulating pump and connecting pipes.

[0015] A cooling water inlet is provided at the middle and upper part of the side wall of the cooling tower, a high-temperature fluid inlet is provided at the middle and lower part of the side wall of the cooling tower, a gas outlet is provided at the top of the cooling tower, a cold water outlet is provided at the bottom of the cooling tower, a cooling and defoaming layer is provided inside the cooling tower between the subcritical salt water inlet and the flash gas outlet, the circulating pump inlet is connected to the cooling water tower through a pipeline, the circulating pump outlet is connected to the cooling water inlet of the cooling tower through a pipeline, the cold water outlet of the cooling tower is connected to the cooling water tower through a pipeline, and the fan is located above the cooling water tower;

[0016] The control system consists of a control cabinet, sensors, actuators and signal transmission lines.

[0017] The sensors include a buffer tank pressure sensor, an air flow meter sensor, a preheating temperature sensor, a reaction temperature sensor, a reaction pressure sensor, a shell and tube heat exchanger pipe outlet temperature sensor, a subcritical brine tank temperature sensor, a subcritical brine tank pressure sensor, a cooling tower temperature sensor, and a cooling tower temperature sensor. The actuators include a clean water valve switch, a sewage valve switch, a high-pressure feed pump switch, an air compressor switch, an air flow regulating valve switch, an air pulse purge valve switch, an electromagnetic preheater switch, an electromagnetic heating coil switch, a high-temperature fluid electric regulating outlet valve switch, a high-temperature salt discharge valve switch, a low-temperature salt discharge valve switch, a cold water plunger pump switch, a fan switch, and a circulating pump switch. The sensors and actuators are connected to the control cabinet via a signal transmission line.

[0018] Preferably, in the feeding system, the working pressure of the buffer tank is 28-30MPa; the outlet temperature of the waste heat preheater and the electromagnetic preheater is 260-300°C, and when the preheating pipeline is slightly blocked and the air feed flow rate begins to decrease, the air pulse purge valve automatically opens to realize automatic pulse purge of the feed pipeline.

[0019] Preferably, the working pressure of the reaction system is 22.5-25MPa, the working temperature is 500-600°C, and the peroxygen coefficient is 1.2-1.5; the high-temperature fluid is cooled to below 300°C through the shell and tube heat exchanger; the anti-corrosion lining layer of the outer cylinder is a 2-6mm thick nickel-based alloy material, and the pressure-bearing wall is made of magnetic carbon steel material that is convenient for electromagnetic heating; the insulation layer is a 10-30mm thick high-temperature resistant aerogel material, and the C-type sealing ring is made of a nickel-based alloy material.

[0020] Preferably, in the salt removal system, the pressure of the subcritical brine tank is 10-15MPa, the temperature is 200-300°C, the flash pressure of the brine flash tank is normal pressure, the flash temperature is above 100°C, and the opening pressure of the automatic pressure regulating valve is 10-15MPa, that is, when the subcritical brine tank is pressurized to 10-15MPa, the automatic pressure regulating valve will automatically open, and the outlet water of the shell and tube heat exchanger will automatically enter the cooling tower in the cooling system for cooling.

[0021] Preferably, in the cooling system, the cooling tower cools the high-temperature fluid from the high-temperature fluid electric regulating outlet valve and the flash gas from the brine flash tank to below 50°C, and the cooling water tower cools the circulating water to below 35°C through a fan.

[0022] The advantages of the present invention are:

[0023] 1. The present invention controls the material preheating temperature in the range of 260-300°C, and at the same time reduces the pipeline blockage caused by high-temperature precipitation of salt and low-temperature coking of organic matter; at the same time, a pulse purge pipeline is set to automatically pulse purge the feed pipeline, which completely solves the blockage problem of the feed system;

[0024] 2. By setting up a subcritical brine tank with a pressure of 10-15MPa and a temperature of 200-300℃, the salt is discharged in the form of subcritical brine, thereby avoiding the wear of the valve by solid salt; by setting up a brine flash tank, the subcritical brine can be flashed to obtain solid salt. In addition, the subcritical brine tank reduces the temperature of the salt discharge valve and the pressure difference on both sides.

[0025] 3. The use of a carbon steel pressure-bearing wall lined with a nickel-based alloy not only achieves corrosion protection and cost reduction for the reactor, but also greatly improves the efficiency of electromagnetic heating.

[0026] 4. By optimizing the energy recovery process of the entire system, the operating cost is reduced. This system has effectively solved the problems of blockage, corrosion and high cost of the supercritical continuous oxidation system of high-salt and high-concentration organic wastewater, and has broad prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a supercritical continuous oxidation system for high-salt and high-concentration organic wastewater.

[0028] Figure 2 This is the control system diagram.

[0029] Figure 3 This is the structural diagram of the reaction system.

[0030] Figure 4 This is the structural diagram of the brine flash tank.

[0031] Figure 5 This is the cooling tank structure diagram.

[0032] In the above figure: 1-1, clean water tank; 1-2, clean water valve; 1-3, sewage tank; 1-4, sewage valve; 1-5, high-pressure feed pump; 1-6, air compressor; 1-7, buffer tank; 1-8, air flow control valve; 1-9, air flow meter; 1-10, air pulse purge valve; 1-11, jet mixer; 1-12, waste heat preheater; 1-13, electromagnetic preheater; 2-1, upper end cover; 2-1-1, feed port; 2-1-2, temperature measuring port; 2-1-3, pressure relief port; 2-2, inner cylinder; 2-3, temperature measuring sleeve; 2-4, conical guide plate; 2-5, outer cylinder; 2-5-1, salt discharge port; 2-5-2, high temperature Fluid outlet; 2-5-3, anti-corrosion lining; 2-5-4, pressure-bearing wall; 2-6, C-type sealing ring; 2-7, insulation layer; 2-8, electromagnetic heating coil; 2-9, bursting disc; 2-10, high-temperature fluid electric regulating outlet valve; 3-1, high-temperature salt discharge valve; 3-2, subcritical brine tank; 3-3, low-temperature salt discharge valve; 3-4, brine flash tank; 3-4-1, subcritical brine inlet; 3-4-2, solid salt outlet; 3-4-3, flash gas outlet; 3-4-4, flash defoaming layer; 3-5, cold water plunger pump; 3-6, shell and tube heat exchanger; 3-7, automatic pressure regulating valve; 4-1, cooling tower; 4-1-1, cooling water inlet 4-1-2, high-temperature fluid inlet; 4-1-3, gas outlet; 4-1-4, cold water outlet; 4-1-5, cooling and defoaming layer; 4-2, cooling water tower; 4-3, fan; 4-4, circulating pump; 5-1, control cabinet; 5-2, sensor; 5-2-1, buffer tank pressure sensor; 5-2-2, preheating temperature sensor; 5-2-3, reaction temperature sensor; 5-2-4, reaction pressure sensor; 5-2-5, shell and tube heat exchanger tube outlet temperature sensor; 5-2-6, subcritical brine tank temperature sensor; 5-2-7, subcritical brine tank pressure sensor; 5-2-8, cooling tower temperature sensor; 5-2 -9, cooling tower temperature sensor; 5-3, actuator; 5-3-1, clean water valve switch; 5-3-2, sewage valve switch; 5-3-3, high-pressure feed pump switch; 5-3-4, air compressor switch; 5-3-5, air flow control valve switch; 5-3-6, air pulse purge valve switch; 5-3-7, electromagnetic preheater switch; 5-3-8, electromagnetic heating coil switch; 5-3-9, high-temperature fluid electric regulating outlet valve switch; 5-3-10, high-temperature salt discharge valve switch; 5-3-11, low-temperature salt discharge valve switch; 5-3-12, cold water plunger pump switch; 5-3-13, fan switch; 5-3-14, circulation pump switch. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only explanations that make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, and are not limitations of the present invention:

[0034] First, start the fan (4-3) and the circulation pump (5-1) to circulate the cooling water. Start the air compressor (1-6) to introduce high-pressure air into the buffer tank (1-7), and keep the pressure of the buffer tank (1-7) at 28-30MPa. Open the air flow regulating valve (1-8) to discharge the high-pressure air from the buffer tank (1-7); at the same time, open the clean water valve (1-2) to introduce clean water, and start the high-pressure feed pump (1-5) to provide pressure for the clean water. After the high-pressure clean water and high-pressure air are fully mixed in the jet mixer (1-11), they pass through the waste heat preheater (1-12) pipe and the electromagnetic preheater (1-13) and enter the reaction system (2). Start the electromagnetic preheater (1-13) and the electromagnetic heating coil (2-8) to heat the system, and by adjusting the opening of the high-temperature fluid electric regulating outlet valve (2-10), the system pressure is controlled within the range of 22.5-25MPa.

[0035] Furthermore, when the system temperature and pressure reach 500-600°C and 22.5-25MPa respectively, the clean water valve (1-2) is closed and the sewage valve (1-4) is opened at the same time to convert the clean water feed into sewage feed. The sewage is pressurized to 22.5-25MPa by the high-pressure feed pump (1-5), and is fully mixed with the high-pressure air from the buffer tank (1-7) in the jet mixer (1-11). After being heated to the range of 260-300°C by the waste heat preheater (1-12) and the electromagnetic preheater (1-13), it enters the reaction system (2) from the feed port (2-1-1) of the upper end cover (2-1).

[0036] Furthermore, when the feed pipeline is slightly blocked and the air feed flow rate begins to decrease, the air pulse purge valve (1-10) automatically opens to achieve automatic pulse purge of the feed pipeline.

[0037] Furthermore, the preheated material enters the reaction system (2), and under the action of the electromagnetic heating coil (2-8), the temperature is further increased to 500-600°C, and a supercritical water oxidation reaction occurs in the inner cylinder (2-2), the reaction generates high-temperature fluids such as CO2, H2O and N2, and high-temperature salt is precipitated at the same time.

[0038] Furthermore, the high-temperature fluid generated by the reaction is discharged from the high-temperature fluid outlet (2-5-2) of the outer tube (2-5), cooled to below 300°C through the tube side of the shell and tube heat exchanger (3-6), and then enters the tube side of the waste heat preheater (1-12) to exchange heat with the preheated material in the tube side, and finally discharged from the reaction system (2) through the high-temperature fluid electric regulating outlet valve (2-10) and enters the cooling system (4).

[0039] Furthermore, the cold water is increased in pressure to 10-15 MPa by a cold water plunger pump (3-5), and then enters the shell side of the shell-and-tube heat exchanger (3-6), cools the high-temperature fluid in the tube side, and increases its own temperature to 200-300° C. At this time, the cold water becomes subcritical water and enters the subcritical brine tank (3-2). When the subcritical brine tank (3-2) is full and the pressure is increased to 10-15 MPa, the automatic pressure regulating valve (3-7) automatically opens, and the subcritical water directly enters the cooling tower (4-1) in the cooling system (4) through the automatic pressure regulating valve (3-7) for cooling.

[0040] Furthermore, the high-temperature salt precipitated by the reaction falls to the lower end of the outer cylinder (2-5) by gravity, and dissolves into the subcritical water therein to form subcritical brine. When discharging salt, first open the high-temperature salt discharge valve (3-1), and the subcritical brine enters the subcritical brine tank (3-2) under the action of the pressure difference; then, completely close the high-temperature salt discharge valve (3-1), open the low-temperature salt discharge valve (3-3), and the subcritical brine enters the brine flash tank (3-2) under the action of the pressure difference, flash to obtain solid salt, and discharge the high-temperature gas from the flash gas outlet (3-4-3) into the cooling tower (4-1) of the cooling system (4); finally close the low-temperature salt discharge valve. Repeat the above steps to discharge salt.

[0041] Furthermore, the circulating cooling water enters the cooling tower (4-1) from the cooling tower (4-2) under the action of the circulating pump (4-4), cools the high-temperature fluid discharged from the reaction system (2) and the flash gas from the brine flash tank (3-4) to below 50°C, and then transports them back to the cooling tower (4-2), and releases the non-condensable gas. The circulating cooling water in the cooling tower (4-2) is cooled to below 35°C by the fan (4-3).

Claims

1. A supercritical continuous oxidation system for high-salt and high-concentration organic wastewater, characterized by: It comprises a feeding system (1), a reaction system (2), a salt removal system (3), a cooling system (4) and a control system (5); The feeding system (1) is composed of a clean water tank (1-1), a clean water valve (1-2), a sewage tank (1-4), a sewage valve (1-4), a high-pressure feeding pump (1-5), an air compressor (1-6), a buffer tank (1-7), an air flow regulating valve (1-8), an air flow meter (1-9), an air pulse purge valve (1-10), a jet mixer (1-11), a waste heat preheater (1-12), an electromagnetic preheater (1-13) and connecting pipelines. The clean water tank (1-1) and the clean water valve (1-2) are connected in series to form a clean water pipeline, the sewage tank (1-4) and the sewage valve (1-4) are connected in series to form a sewage pipeline, the clean water pipeline and the sewage pipeline are connected in parallel to the inlet of the high-pressure feed pump (1-5), the air compressor (1-6), the buffer tank (1-7), the air flow regulating valve (1-8), and the air flow meter (1-9) are connected in series in sequence through pipelines to form an intake pipeline, and the air pulse purge valve (1-10) is connected in parallel with the air flow regulating valve (1-8) and the air flow meter (1-9) to form a pulse purge pipe. The liquid inlet of the jet mixer (1-11) is connected to the outlet of the high-pressure feed pump (1-5) through a pipeline, the gas inlet is connected to the outlet of the air flow meter (1-9) and the outlet of the air pulse purge valve (1-10) through pipelines, the outlet of the jet mixer (1-11) is connected to the pipe side inlet of the waste heat preheater (1-12) through a pipeline, the pipe side outlet of the waste heat preheater (1-12) is connected to the inlet of the electromagnetic preheater (1-13), and the outlet of the electromagnetic preheater (1-13) is connected to the feed port (2-1-1) of the reaction system (2) through a pipeline; The reaction system (2) is composed of an upper end cover (2-1), an inner cylinder (2-2), a temperature measuring sleeve (2-3), a conical guide plate (2-4), an outer cylinder (2-5), a C-type sealing ring (2-6), an insulating layer (2-7), an electromagnetic heating coil (2-8), a bursting disc (2-9), a high-temperature fluid electric regulating outlet valve (2-10) and connecting pipelines. The upper end cover (2-1) is provided with a feed port (2-1-1), a temperature measuring port (2-1-2) and a pressure relief port (2-1-3), and the feed port (2-1-1) is located at the center of the upper end cover (2-1); the upper end of the inner tube (2-2) is coaxially fixed to the upper end cover (2-1) with the feed port (2-1-1), and the temperature measuring port (2-1-2) and the pressure relief port (2-1-3) are located in the inner tube (2-2); the upper end of the temperature measuring sleeve (2-3) is connected to the upper end of the temperature measuring sleeve (2-3) through the temperature measuring port (2-1-1); The outer tube (2-5) is welded to the upper end cover (2-1), and the lower end thereof penetrates into the middle of the inner tube (2-2). A conical guide plate (2-4) is installed at the lower end of the inner tube (2-2). A salt discharge port (2-5-1) is provided at the lower end of the outer tube (2-5). A high-temperature fluid outlet (2-5-2) is provided at the upper part of the side wall of the outer tube (2-5). The outer tube (2-5) is composed of an anti-corrosion lining layer (2-5-3) and a pressure-bearing wall (2-5-4). The upper end cover (2-1) and the outer tube (2-2) are connected to each other. 5) are installed with a C-shaped sealing ring (2-6) and connected by bolts; the insulation layer (2-7) is coated on the outside of the outer cylinder (2-5), the electromagnetic heating coil (2-8) is wound on the outside of the insulation layer (2-7), the bursting disc (2-9) is installed at the pressure relief port (2-1-3) of the upper end cover (2-1), the high-temperature fluid outlet (2-5-2) is connected to the pipe inlet of the shell and tube heat exchanger (3-6) through a pipeline, and the shell and tube heat exchanger (3-6) outlet The waste heat preheater (1-12) is connected to the shell side inlet through a pipeline, the shell side outlet of the waste heat preheater (1-12) is connected to the inlet of the high-temperature fluid electric regulating outlet valve (2-10) through a pipeline, the outlet of the high-temperature fluid electric regulating outlet valve (2-10) is connected to the high-temperature fluid inlet (4-1-2) of the cooling tower (4-1) of the cooling system (4) through a pipeline, and the salt discharge port (2-5-1) is connected to the inlet of the high-temperature salt discharge valve (3-1) of the salt discharge system (3); The salt discharge system (3) is composed of a high-temperature salt discharge valve (3-1), a subcritical brine tank (3-2), a low-temperature salt discharge valve (3-3), a brine flash tank (3-4), a cold water plunger pump (3-5), a casing heat exchanger (3-6), an automatic pressure regulating valve (3-7) and connecting pipelines. The high-temperature salt discharge valve (3-1), the subcritical salt water tank (3-2), and the low-temperature salt discharge valve (3-3) are connected in sequence from top to bottom; a subcritical salt water inlet (3-4-1) is provided at the middle and upper part of the side wall of the salt water flash tank (3-4); a solid salt outlet (3-4-2) is provided at the bottom; and a flash gas outlet (3-4-3) is provided at the top; a flash defoaming layer (3-4-4) is provided inside the salt water flash tank (3-4) between the subcritical salt water inlet (3-4-1) and the flash gas outlet (3-4-3); the inlet of the cold water plunger pump (3-5) is connected to the cold water tower (4-2) of the cooling system (4) through a pipeline; and the outlet of the cold water plunger pump (3-5) is connected to the casing through a pipeline. The shell side inlet of the heat exchanger (3-6) is connected, the shell side outlet of the shell side of the tube heat exchanger (3-6) is respectively connected to the subcritical water inlet of the side wall of the subcritical brine tank (3-2) and the inlet of the automatic pressure regulating valve (3-7) through pipelines, the outlet of the automatic pressure regulating valve (3-7) is connected to the cooling water inlet (4-1-1) of the cooling tower (4-1) of the cooling system (4) through a pipeline, the outlet of the low-temperature salt discharge valve (3-3) is connected to the subcritical brine inlet (3-4-1) of the brine flash tank (3-4) through a pipeline, and the flash gas outlet (3-4-3) of the brine flash tank (3-4) is connected to the high-temperature fluid inlet (4-1-2) of the cooling tower (4-1) of the cooling system (4) through a pipeline; The cooling system (4) is composed of a cooling tower (4-1), a cooling water tower (4-2), a fan (4-3), a circulation pump (4-4) and connecting pipelines. A cooling water inlet (4-1-1) is provided at the middle and upper part of the side wall of the cooling tower (4-1), a high-temperature fluid inlet (4-1-2) is provided at the middle and lower part of the side wall of the cooling tower (4-1), a gas outlet (4-1-3) is provided at the top of the cooling tower (4-1), a cold water outlet (4-1-4) is provided at the bottom of the cooling tower (4-1), a cooling and defoaming layer (4-1-5) is provided inside the cooling tower (4-1) between the subcritical salt water inlet (3-4-1) and the flash gas outlet (3-4-3), the inlet of the circulating pump (4-4) is connected to the cooling water tower (4-2) through a pipeline, the outlet of the circulating pump (4-4) is connected to the cooling water inlet (4-1-1) of the cooling tower (4-1) through a pipeline, the cold water outlet (4-1-4) of the cooling tower (4-1) is connected to the cooling water tower (4-2) through a pipeline, and the fan (4-3) is located above the cooling water tower (4-2); The control system (5) is composed of a control cabinet (5-1), a sensor (5-2), an actuator (5-3) and a signal transmission line. The sensor (5-2) includes a buffer tank pressure sensor (5-2-1), an air flow meter sensor (5-2-2), a preheating temperature sensor (5-2-3), a reaction temperature sensor (5-2-4), a reaction pressure sensor (5-2-5), a shell and tube heat exchanger tube outlet temperature sensor (5-2-6), a subcritical brine tank temperature sensor (5-2-7), a subcritical brine tank pressure sensor (5-2-8), a cooling tower temperature sensor (5-2-9), and a cooling tower temperature sensor (5-2-10); the actuator (5-3) includes a clean water valve (1-2) switch (5-3-1), a sewage valve (1-4) switch (5-3-2), a high-pressure feed pump (1-5) switch (5-3-3), and an air compressor (1-6) switch. (5-3-4), air flow regulating valve (1-8) switch (5-3-5), air pulse purge valve (1-10) switch (5-3-6), electromagnetic preheater (1-13) switch (5-3-7), electromagnetic heating coil (2-8) switch (5-3-8), high temperature fluid electric regulating outlet valve (2-10) switch (5-3-9), high temperature salt discharge valve (3-1) switch (5-3-10), low temperature salt discharge valve (3-3) switch (5-3-11), cold water plunger pump (3-5) switch (5-3-12), fan (4-3) switch (5-3-13), circulation pump (4-4) switch (5-3-14), the sensor (5-2) and the actuator (5-3) are connected to the control cabinet (5-1) through a signal transmission line.

2. The feeding system (1) according to claim 1, characterized in that: The working pressure of the buffer tank (1-7) is 28-30MPa; the outlet temperatures of the waste heat preheater (1-12) and the electromagnetic preheater (1-13) are 260-300°C, and when the preheating pipeline is slightly blocked and the air feed flow rate begins to decrease, the air pulse purge valve (1-10) automatically opens to achieve automatic pulse purge of the feed pipeline.

3. The reaction system (2) according to claim 1, characterized in that: The working pressure is 22.5-25MPa, the working temperature is 500-600°C, and the oxygen permeability coefficient is 1.2-1.5; the high-temperature fluid is cooled to below 300°C through the shell and tube heat exchanger (3-6); the anti-corrosion lining layer (2-5-3) of the outer cylinder (2-5) is a nickel-based alloy material with a thickness of 2-6mm, and the pressure-bearing wall (2-5-4) is made of magnetic carbon steel material that is convenient for electromagnetic heating; the insulation layer (2-7) is a high-temperature resistant aerogel material with a thickness of 10-30mm, and the C-type sealing ring (2-6) is made of a nickel-based alloy material.

4. The salt removal system (3) according to claim 1, characterized in that: The pressure of the subcritical brine tank (3-2) is 10-15 MPa and the temperature is 200-300° C. The flash pressure of the brine flash tank (3-4) is normal pressure and the flash temperature is above 100° C. The opening pressure of the automatic pressure regulating valve (3-7) is 10-15 MPa, that is, when the pressure of the subcritical brine tank (3-2) is increased to 10-15 MPa, the automatic pressure regulating valve (3-7) will automatically open, and the outlet water of the shell and tube heat exchanger (3-6) will automatically enter the cooling tower (4-1) in the cooling system (4) for cooling.

5. The cooling system (4) according to claim 1, characterized in that: The cooling tower (4-1) cools the high-temperature fluid from the high-temperature fluid electric regulating outlet valve (2-10) and the flash gas from the brine flash tank (3-4) to below 50°C, and the cooling water tower (4-2) cools the circulating water to below 35°C through the fan (4-3).

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