A swirl-flow supercritical water combustion device and method

Abstract

A swirling-flow supercritical hydrothermal combustion device and method. The device includes a number of hydrothermal flame generators evenly distributed circumferentially on the upper part of the device main body. Each hydrothermal flame generator is provided with a high-pressure organic slurry input branch pipe and a high-pressure oxidant input branch pipe. The geometric axes of the output ports of each hydrothermal flame generator are all tangent to the imaginary circle of the core combustion zone inside the device. A burnout slag slurry converging cone is arranged at the lower part of the device main body. The burnout slag slurry converging cone is connected to the supercritical thermal fluid guiding cone below it. Several burnout slag slurry outlets D are arranged on the upper part of the side surface of the burnout slag slurry converging cone. A supercritical thermal fluid outlet C is arranged at the bottom of the supercritical thermal fluid guiding cone. The present invention realizes the rapid ignition, efficient and clean combustion of solid-phase or solid-containing fuels such as fossil fuels (such as coal), urban / industrial sludge, etc., and the effective separation of the slag flow after burnout, and is an advanced combustion technology that promotes the efficient and pollution-free conversion of chemical energy into thermal energy.

Description

Technical Field

[0001] The present invention belongs to the technical field of advanced combustion, energy conservation and environmental protection, and particularly relates to a swirl-type supercritical hydrothermal combustion device and method. Background Art

[0002] Supercritical water refers to water in a special state where both the temperature and pressure are higher than its critical point (Tc = 374.15 °C, Pc = 22.12 MPa). Supercritical water oxidation technology utilizes the special properties of supercritical water such as low viscosity, low dielectric constant, and high diffusivity to enable the organic matter completely dissolved in it to undergo a rapid and thorough homogeneous reaction with the oxidant. The carbon element in the organic matter is converted into carbon dioxide, elements such as chlorine, sulfur, and phosphorus are converted into corresponding inorganic salts, and the vast majority of nitrogen elements are converted into nitrogen gas, achieving the efficient and harmless treatment of organic waste. Supercritical water oxidation is a green, efficient, and thorough technology for the harmless treatment and disposal of organic waste, and is regarded as the most promising organic waste treatment technology in the 21st century. Supercritical water combustion technology is a new international advanced combustion technology, which can be regarded as an intense supercritical water oxidation technology that generates a "hydrothermal flame", and is also called a combustion technology of "water and fire coexisting". The local high temperature above 1000 °C in the hydrothermal flame zone can achieve the rapid oxidative degradation of organic matter in fossil fuels and pollutants, while releasing abundant heat.

[0003] Currently, the problems of salt deposition and corrosion have restricted to a certain extent the low-cost and reliable industrial implementation of supercritical water oxidation technology. Among them, the high-pressure 300 - 410 °C high-temperature zone is the material corrosion sensitive zone and the rapid precipitation zone of inorganic salts in the supercritical water oxidation process system. The equipment serving in this working condition area faces relatively severe corrosion and the risk of blockage caused by salt deposition. If the supercritical hydrothermal flame is used to mix with lower-temperature materials (<300 °C) to achieve the rapid temperature rise of the latter, or directly achieve the rapid ignition and combustion of lower materials in the supercritical hydrothermal flame, the high-incidence area of equipment corrosion and salt deposition blockage in the 300 - 410 °C temperature zone can be avoided. In addition, in the energy field, conventional coal-fired power generation systems and coal-fired industrial boilers are, in principle, "burning coal in one go" in a gaseous environment with air as the oxidant. The industrial pollutants such as fly ash, sulfur oxides, and nitrogen oxides generated have caused huge environmental pollution. The supercritical hydrothermal combustion of fossil fuels such as coal is a technology with very broad prospects. The supercritical hydrothermal combustion of coal is a new combustion technology that can achieve the efficient and clean utilization of coal without the need for end-of-pipe control of pollutants. Compared with the conventional combustion technology of coal, the supercritical hydrothermal combustion technology of coal can achieve the pollutants NO x 、SO x, The source control of dust can easily achieve low-cost capture of CO2 and has extremely excellent environmental protection performance. However, the hydrothermal combustion of solid fuels such as coal and sludge still generates solid-phase combustion ash slurries. If not properly disposed of, it will clog subsequent devices and affect the normal operation of the whole. Therefore, a hydrothermal combustion device that can achieve rapid ignition of fuel and effective separation of slag flow after burnout is the key to realizing the efficient and clean combustion of solid-phase or solid-containing fuels such as coal and sludge. Summary of the Invention

[0004] In order to overcome the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a swirl-type supercritical hydrothermal combustion device and method, which realizes the rapid ignition, efficient and clean combustion of solid-phase or solid-containing fuels such as fossil fuels (such as coal), urban / industrial sludge, etc., and effective separation of slag flow after burnout, and is an advanced combustion technology that promotes the efficient and pollution-free conversion of chemical energy into thermal energy.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A swirl-type supercritical hydrothermal combustion device includes a plurality of hydrothermal flame generators 5 evenly distributed circumferentially on the upper part of the device main body 2. Each hydrothermal flame generator 5 is provided with a high-pressure organic slurry input branch pipe 8 and a high-pressure oxidant input branch pipe 9. The geometric axes of the output ports of each hydrothermal flame generator 5 are all tangent to the imaginary circle of the inner core combustion zone of the device. A burnout slag slurry converging cone 3 is arranged at the lower part of the device main body 2. The burnout slag slurry converging cone 3 is connected to the supercritical heat fluid guiding cone 4 below it. A plurality of burnout slag slurry outlets D are arranged on the upper part of the side surface of the burnout slag slurry converging cone 3, and a supercritical heat fluid outlet C is arranged at the bottom of the supercritical heat fluid guiding cone 4.

[0007] Furthermore, the device main body 2 is wrapped with an efficient cooling jacket 1. The efficient cooling jacket 1 is a jacket structure or a single-layer / multilayer spiral channel structure, and the coolant is water, air, heat-conducting oil, organic slurry, oxidant, etc.

[0008] Furthermore, the high-pressure organic slurry branch pipe 8 is connected to the high-pressure organic slurry distribution pipe 6, the high-pressure oxidant branch pipe 9 is connected to the high-pressure oxidant distribution pipe 7, the high-pressure organic slurry branch pipe 8 and the high-pressure oxidant branch pipe 9 are both connected to each hydrothermal flame generator 5 at the same time, and the pressures at the inlet A of the high-pressure organic slurry distribution pipe 6 and the inlet B of the high-pressure oxidant distribution pipe 7 are both not lower than 23 MPa.

[0009] Furthermore, the number of the hydrothermal flame generators 5 is 3 or 4. The arrangement of the hydrothermal flame generators 5 ensures that the burnout slag slurry and the supercritical fluid move downward in a rotating manner, which is beneficial to the separation of the burnout slag slurry from the supercritical heat fluid at the burnout slag slurry converging cone 3.

[0010] Further, the burnout slag slurry converging cone 3 includes, but is not limited to, a microporous structure. It can adopt a frustum shape, with a large number of micropores distributed circumferentially, and a single large hole or a medium-sized hole is provided at the top.

[0011] Further, an inlet pipe of a flow control valve 10 is connected to the burnout slag slurry outlet D. The number of burnout slag slurry outlets D can be 1, 2, 3, etc.

[0012] The present invention also provides a swirling supercritical hydrothermal combustion method based on the swirling supercritical hydrothermal combustion device. When the device is started, first, the treated supercritical water is injected from the high-pressure organic slurry branch pipe 8 into the hydrothermal flame generator 5, and then sprayed into the device main body 2. At this time, the high-pressure oxidant distribution pipe 7 is in a closed state;

[0013] After the supercritical water fills the entire device main body 2, the organic slurry is switched in the high-pressure organic slurry branch pipe 8, and at the same time, the high-pressure oxidant distribution pipe 7 is opened to inject the oxidant. The organic slurry and the oxidant cause thermal spontaneous ignition in the hydrothermal flame generator 5 and enter the device main body 2 in the form of a fire tongue. The spiral flow of the fluid in the device main body 2 causes the fire tongue to start spiral movement;

[0014] After ignition, the wall temperature of the device main body 2 is controlled below 500 °C through the cooling structure.

[0015] Further, when performing the operation of discharging the burnout slag slurry, the flow rate of the burnout slag slurry is controlled by the flow control valve 10 to prevent the outflow from being too fast and affecting the outflow stability of the product at the supercritical heat fluid outlet C. The device main body 2 is continuously cooled throughout the process.

[0016] Further, the oxidant is liquid oxygen, oxygen, air, etc., and the organic slurry is coal slurry, municipal sludge, oil sludge, petrochemical residue, etc.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. A number of hydrothermal combustion generators are arranged around the equipment. The geometric axes of the outlets of each hydrothermal flame generator are tangent to the imaginary circle at the center of the device. Therefore, the flame jets of the hydrothermal flame generators form a rotating supercritical hydrothermal fireball in the device. Affected by the oblique impact of the high-temperature flame ejected from the upstream hydrothermal flame generator, the ignition conditions of the organic slurry at the downstream hydrothermal flame generator are excellent, which is conducive to the stable ignition and enhanced combustion of the organic slurry; the rotating supercritical hydrothermal fireball can make the solid-phase particles rotate in the device, extend their flow path, and is conducive to burnout. After burnout at the lower part of the device, the solid-phase particles in the supercritical fluid containing solids gather at the bottom of the burnout slag slurry converging cone under the action of rotational centrifugal force; in addition, the microporous burnout slag slurry converging cone has a filtering effect on the solid-phase particles, thereby realizing the efficient self-separation of the slag slurry and the supercritical heat fluid after burnout.

[0019] 2. After supercritical water thermal combustion, sulfur and most nitrogen in the fuel enter the ash slurry in the form of sulfates and nitrates / nitrites. The main components of the separated supercritical liquid-phase fluid are supercritical water, carbon dioxide, nitrogen, and a small amount of surplus oxygen, thus achieving the source control of pollutants NO x , SO x , dust, and it is easy to achieve low-cost capture of CO2, with extremely excellent environmental protection performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of the device of the present invention.

[0021] Figure 2 is a schematic diagram of the hydrothermal flame generator of the present invention and its layout form.

[0022] Wherein: 1. High-efficiency cooling jacket; 2. Device main body; 3. Ash slurry convergence cone; 4. Supercritical thermal fluid guiding cone; 5. Hydrothermal flame generator; 6. High-pressure organic slurry distribution pipe; 7. High-pressure oxidant distribution pipe; 8. High-pressure organic slurry branch pipe; 9. High-pressure oxidant branch pipe; 10. Flow control valve; A. High-pressure organic slurry distribution pipe inlet; B. High-pressure oxidant distribution pipe inlet; C. Supercritical thermal fluid outlet; D. Ash slurry outlet; E. Cooling water inlet; F. Cooling water outlet; A-I, A-II, A-III are all high-pressure organic slurry distribution pipe inlets; B-I, B-II, B-III are all high-pressure oxidant distribution pipe inlets; 5a, 5b, 5c are all hydrothermal flame generators. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to enable those skilled in the art to better understand the solution 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 accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] The present invention will be further described in detail below with reference to the accompanying drawings:

[0026] As Figure 1 shown, the high-pressure organic slurry distribution pipe 6 is divided into multiple high-pressure organic slurry input branch pipes 8, and the high-pressure oxidant distribution pipe 7 is divided into multiple high-pressure oxidant input branch pipes 9. Each high-pressure organic slurry input branch pipe 8 and high-pressure oxidant input branch pipe 9 are connected to each hydrothermal flame generator 5. The pressures at the inlet A of the high-pressure organic slurry distribution pipe and the inlet B of the high-pressure oxidant distribution pipe are not less than 23 MPa. A number of hydrothermal flame generators 5 are circumferentially and evenly distributed in a special manner on the upper part of the hydrothermal combustion device. As Figure 2 shown, in this embodiment, there are a total of 3 hydrothermal flame generators 5, namely hydrothermal flame generator one 5a, hydrothermal flame generator two 5b and hydrothermal flame generator three 5c. Hydrothermal flame generator one 5a is connected to the inlet A-I of the high-pressure organic slurry distribution pipe and the inlet B-I of the high-pressure oxidant distribution pipe. Hydrothermal flame generator two 5b is connected to the inlet A-II of the high-pressure organic slurry distribution pipe and the inlet B-II of the high-pressure oxidant distribution pipe. Hydrothermal flame generator three 5c is connected to the inlet A-III of the high-pressure organic slurry distribution pipe and the inlet B-III of the high-pressure oxidant distribution pipe. The geometric axes of the outlets of each hydrothermal flame generator are all tangent to the imaginary circle of the core combustion zone in the device, so as to ensure the formation of subsequent spiral flames. The device main body 2 is wrapped by an efficient cooling sleeve 1 with a jacket structure or a single-layer / multilayer spiral channel structure. The cooling water in the cooling sleeve 1 enters from the cooling water inlet E at the top and flows out through the cooling water outlet F. The burnt ash slurry converging cone 3 at the bottom of the device main body 2 is connected to the supercritical heat fluid guiding cone 4. There are several burnt ash slurry outlets D on the upper part of the side of the burnt ash slurry converging cone 3, and a supercritical heat fluid outlet C is provided at the bottom of the supercritical heat fluid guiding cone 4.

[0027] When the device starts, first, the supercritical water that has been treated up to standard (taking 400°C and 23 MPa as an example) is injected from the inlet A of the high-pressure organic slurry distribution pipe, passes through the high-pressure organic slurry distribution pipe 6 to the high-pressure organic slurry branch pipe 8, and then is injected into the hydrothermal flame generator 5, and finally sprayed into the device main body 2. At this time, the high-pressure oxidant distribution pipe 7 is in a closed state. After the supercritical water fills the entire device main body 2, the fluid at the inlet A of the high-pressure organic slurry distribution pipe is switched to organic slurry (taking coal slurry as an example), and at the same time, the high-pressure oxidant distribution pipe 7 is opened, and oxidant (taking air as an example) at the same temperature and pressure (such as 550°C and 25 MPa) is injected. The coal slurry and air are thermally auto-ignited in the hydrothermal flame generator 5 and enter the device main body 2 in the form of a flame tongue. At the same time, due to the configuration method of multiple generators 5, the spiral flow of the fluid in the device main body 2 causes the flame tongue to also start to spiral. After ignition, normal-temperature coolant (taking pure water as the coolant here) is introduced from the cooling water inlet E, and the high-efficiency cooling jacket 1 is started to control the wall temperature of the device main body 1 below 500°C.

[0028] When the device operates stably, due to the arrangement method that the geometric axes of the output ports of each hydrothermal flame generator 5 are all tangent to the imaginary circle of the core combustion area in the device, the ejected flame tongues are intertwined and move downward in a spiral column shape, while driving the surrounding fluid to rotate in the same way. Therefore, the flame column persists, and the burned slag slurry continuously deposits in the depression of the burned slag slurry convergence cone 3 due to inertia. The coal slurry, oxidant, and cooling water are all continuously introduced into the device according to the established flow rates.

[0029] When the device performs the operation of discharging the burned slag slurry, the flow rate of the burned slag slurry is controlled by the flow rate regulating valve 10 to prevent the outflow from being too fast and affecting the outflow stability of the products at the supercritical thermal fluid outlet C. The cooling water continuously cools the device main body 2 throughout the process.

[0030] In summary, using this kind of swirl-type supercritical water combustion device and method for the combustion of solid-phase or solid-containing fuels such as coal and sludge can achieve source control of pollutants NO x 、SO x 、dust, can easily achieve low-cost capture of CO2, and has extremely excellent environmental protection performance.

Claims

1. A swirling-flow supercritical hydrothermal combustion device, characterized in that, It includes a number of hydrothermal flame generators (5) evenly distributed circumferentially on the upper part of the device main body (2). Each hydrothermal flame generator (5) is provided with a high-pressure organic slurry input branch pipe (8) and a high-pressure oxidant input branch pipe (9). The geometric axes of the output ports of each hydrothermal flame generator (5) are all tangent to the imaginary circle of the core combustion area inside the device. A burnout slag slurry converging cone (3) is arranged at the lower part of the device main body (2). The burnout slag slurry converging cone (3) adopts a frustum-shaped contour. A large number of micropores are distributed circumferentially at the top of the burnout slag slurry converging cone (3). A single large hole or a large number of medium-sized holes are opened in the middle of the top of the burnout slag slurry converging cone (3). The device main body (2) is connected to the supercritical heat fluid guiding cone (4) through the single large hole or medium-sized holes; the outside of the burnout slag slurry converging cone (3) is connected to the supercritical heat fluid guiding cone (4) below it. Several burnout slag slurry outlets D are provided at the upper part of the outside of the burnout slag slurry converging cone (3). A supercritical heat fluid outlet C is provided at the bottom of the supercritical heat fluid guiding cone (4); the number of the hydrothermal flame generators (5) is 3 or 4. The arrangement of the hydrothermal flame generators (5) ensures that the burnout slag slurry and the supercritical fluid move downward in a rotating manner, which is beneficial to the separation of the burnout slag slurry from the supercritical heat fluid at the burnout slag slurry converging cone (3).

2. The swirling-flow supercritical hydrothermal combustion device according to claim 1, characterized in that, The outside of the device main body (2) is wrapped with an efficient cooling jacket (1). The efficient cooling jacket (1) is a jacket structure, or the efficient cooling jacket (1) is a single-layer or multi-layer spiral channel structure, and the coolant is water, air, heat-conducting oil, organic slurry or oxidant.

3. The swirling-flow supercritical hydrothermal combustion device according to claim 1, characterized in that, The high-pressure organic slurry input branch pipe (8) is connected to the high-pressure organic slurry distribution pipe (6), and the high-pressure oxidant branch pipe (9) is connected to the high-pressure oxidant distribution pipe (7). The high-pressure organic slurry input branch pipe (8) and the high-pressure oxidant branch pipe (9) are both connected to each hydrothermal flame generator (5) at the same time. The pressures at the inlet A of the high-pressure organic slurry distribution pipe (6) and the inlet B of the high-pressure oxidant distribution pipe (7) are both not lower than 23 MPa.

4. The swirling-flow supercritical hydrothermal combustion device according to claim 1, characterized in that, The burnout slag slurry outlet D is connected to a pipe of a flow control valve (10), and the number of the burnout slag slurry outlets D is 2 or 3.

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