Supercritical hydrothermal combustion device capable of realizing temperature control and pressure control

Abstract

The invention discloses a supercritical hydrothermal combustion device capable of realizing temperature control and pressure control. The supercritical hydrothermal combustion device comprises a generator end cover, a mixing barrel, a reactor wall and a spiral cooling barrel. A nozzle platform is arranged at the bottom of the reactor end cover, is provided with an oxidant spiral nozzle, and is in threaded connection with an atomizing nozzle to ensure that fuel and an oxidant are uniformly mixed. A heat preservation groove is formed in a connecting barrel so that it can be guaranteed that the fuel is heated to the set temperature by a heating rod. Water in a cooling spiral channel flows downwards to cool a combustion chamber, then enters a mixing spiral channel and is mixed with reaction fluid flowing out of a mixing barrel outlet hole group, and the temperature control target is achieved. A necking-down structure of the middle of the combustion chamber, a necking-down structure of the bottom of the combustion chamber, the mixing cylinder outlet hole group and the like can achieve the purpose of pressure control.

Description

technical field [0001] The invention belongs to the technical field of supercritical water oxidation, and in particular relates to a supercritical hydrothermal combustion device capable of controlling temperature and pressure. Background technique [0002] Supercritical water means that the temperature and pressure are higher than its critical point (T c =374.15°C, p c =22.12MPa) special state of water. When the temperature and pressure of water exceed its critical point, the physical and chemical properties of water such as density, viscosity, dielectric constant, and ion product will change drastically. Among them, the density is similar to that of liquid, which is 100 to 1000 times larger than that of the corresponding atmospheric pressure gas; the viscosity is close to that of gas, which is about 1% to 10% of the corresponding liquid; the diffusion coefficient is between gas and liquid, which is about 1% to 10% of that of ordinary liquid. 10 to 100 times. In addition...

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Problems solved by technology

For a conventional tubular reactor, the tube wall of the reactor needs to withstand a high temperature of 600-700 ° C and a high pressure of 25 MPa, which must be achieved by using high-temperature resistant materials such as Ni alloy and increasing the wall thickness, which leads to an increase in the construction cost of the reactor. high

[0006] (2) The energy demand of the preheating device is large, and the economy of the reaction system is not high

At present, most of the heating methods of supercritical water oxidation equipment at home and abroad are in the form of electric heating, and the investment cost of high-temperature and high-pressure external preheating equipment is huge, which has caused a huge obstacle to the large-scale industrial application of SCWO technology.

[0007] (3) Material corrosion problem

In addition, heteroatoms such as halogens, sulfur, and phosphorus contained in organic matter will generate corresponding acids during the reaction process, which will further cause corrosion of equipment

[0008] (4) Salt deposition problem

However, in high-temperature and high-pressure environments, with the drastic changes in the physical and chemical properties of water, the solubility of most inorganic salts is extremely low

When the solution is heated from the subcritical temperature to the supercritical temperature, a large amount of inorganic salts originally dissolved in water will be precipitated, which will cause the blockage of the inlet and outlet pipelines of the preheater and the reactor, affect the normal operation of the reactor, and even cause extreme big security risk

[0009] (5) Reaction product handling problem

Increased device operating costs and floor space

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