CN118059757A - Supercritical water self-propagating reaction system - Google Patents

Abstract

The invention discloses a supercritical water self-propagating reaction system, which belongs to the technical field of supercritical water oxidation and comprises a reaction kettle and a heating unit, wherein the reaction kettle comprises a pressure-bearing kettle body and a lining kettle body, a high-pressure cavity is formed between the inner wall of the pressure-bearing kettle body and the outer wall of the lining kettle body, a reaction cavity is formed in the inner cavity of the lining kettle body, a water-oxygen mixed fluid inlet is arranged on the pressure-bearing kettle body, and the heating unit is connected with the water-oxygen mixed fluid inlet and is communicated with the reaction cavity. The invention introduces supercritical water and oxygen into the reaction cavity through the flow guide pipe, firstly oxidizes the bottom raw material, and gradually forms a self-propagating reaction of candle pile type from bottom to top; the high-pressure environment formed by non-corrosive gas is adopted, and double isolation is carried out on corrosive medium by combining with the lining kettle body, so that the corrosion of the external metal pressure-bearing kettle body surface to the corrosive medium is prevented to the greatest extent; the intermittent reaction is adopted to treat the solid waste raw materials with high solid content, so that the recycling of inorganic salt can be effectively completed, and the salt accumulation and blockage can be effectively prevented.

Description

Supercritical water self-propagating reaction system

Technical Field

The invention relates to the field of supercritical water oxidation reactors, in particular to a supercritical water self-propagating reaction system.

Background

Supercritical water is a physical state above the critical temperature (374 ℃) and the critical pressure (22.1 MPa), and in the state, the water has unique physical and chemical properties, such as low viscosity, high diffusivity, adjustable solubility and can be used as a good solvent and a reaction medium, so that the supercritical water oxidation, supercritical water gasification, supercritical water liquefaction and other technologies can be formed, and the supercritical water has wide application potential in the fields of chemical industry, energy, environmental protection and the like.

In the existing supercritical water system (including supercritical water oxidation, supercritical water gasification, supercritical water liquefaction and other technologies), continuous reactors (including tubular reactors, MODAR countercurrent reactors, evaporation wall reactors, cold wall reactors, Y-type reactors and the like) are generally used to place reaction raw materials in water environment, and the raw materials are subjected to oxidation, gasification, liquefaction and other reactions in the reactors in a continuous feeding mode, and reaction products are discharged. However, the existing reactor structure has the following problems:

1. In order to ensure the fluidity of the reaction raw materials and prevent salt deposition from blocking, the solid content in the reaction raw materials is often low, and the raw materials are required to be pretreated, so that the cost of waste treatment per unit mass is increased;

2. in the continuous operation process, cold evaporated water or gas is always required to be continuously injected to protect the pressure-bearing kettle body, so that the energy grade is reduced, and the energy recovery efficiency is reduced;

3. The structure of the continuous reactor is mostly complex, and the equipment manufacturing and operation maintenance costs are high;

4. when the metal wall surface is in contact with the working medium of the critical zone in the reactor, the severe material corrosion of the critical zone can seriously affect the running stability and safety of the equipment.

Disclosure of Invention

The invention aims to provide a supercritical water self-propagating reaction system with high solid content solid waste treatment capacity, which effectively prevents salt accumulation and blockage, has stronger corrosion resistance and prolongs the service life of equipment.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

The utility model provides a supercritical water self-propagating reaction system, includes reation kettle and heating unit, reation kettle includes the pressure-bearing cauldron body and sets up the inside lining cauldron body of the pressure-bearing cauldron body, the pressure-bearing cauldron body with the lining cauldron body is the closed cauldron body, the inner wall of the pressure-bearing cauldron body with form the annular gap between the outer wall of the lining cauldron body to constitute a confined high-pressure chamber, the inner chamber of the lining cauldron body forms a confined reaction chamber, be provided with water oxygen mixed fluid entry and intercommunication on the pressure-bearing cauldron body the high-pressure chamber is with the non-corrosive gas entry of external, control by temperature change water entry and cauldron body export, the reaction chamber through a honeycomb duct with water oxygen mixed fluid entry is linked together, the heating unit through the pipeline with water oxygen mixed fluid entry is linked together.

Preferably, the pressure-bearing kettle body comprises a first kettle body and a first kettle cover which are detachably connected, and the lining kettle body comprises a second kettle body and a second kettle cover which are detachably connected.

Preferably, the honeycomb duct includes first honeycomb duct, second honeycomb duct and the third honeycomb duct that the head and the tail are linked together in proper order, first honeycomb duct sets up on the first cauldron body, the second honeycomb duct sets up first cauldron is covered, the third honeycomb duct sets up on the second cauldron cover, first honeycomb duct keep away from the one end of second honeycomb duct with water oxygen mixed fluid entry is connected, the third honeycomb duct is kept away from the one end setting of second honeycomb duct is in the reaction chamber.

Preferably, the first flow guide pipe is an L-shaped pipe, the second flow guide pipe is a U-shaped pipe, the third flow guide pipe is a straight pipe, the first kettle cover is provided with a first through hole and a second through hole for the two ends of the second flow guide pipe to penetrate through, the second kettle cover is provided with a third through hole for the third flow guide pipe to penetrate through, the axis of the second through hole is coincident with the axis of the third through hole, one end of the second flow guide pipe penetrates through the first through hole and is communicated with the first flow guide pipe, the other end of the second flow guide pipe penetrates through the second through hole and is communicated with the third flow guide pipe, and the third flow guide pipe penetrates through the third through hole.

Preferably, the device further comprises an oxygen supply unit, a non-corrosive gas supply unit, a cooling water supply unit and an energy recovery unit, wherein the non-corrosive gas supply unit is connected with the non-corrosive gas inlet through a pipeline and is communicated with the high-pressure cavity, the heating unit is connected with the water-oxygen mixed fluid inlet and is communicated with the reaction cavity after being converged by the pipeline and the oxygen supply unit, the cooling water supply unit is connected with the temperature control water inlet through a pipeline and is communicated with the high-pressure cavity, and the energy recovery unit is connected with the kettle body outlet through a pipeline.

Preferably, the oxygen supply unit comprises a liquid oxygen storage tank, a liquid oxygen pump and an oxygen heat exchanger which are connected with each other, the non-corrosive gas supply unit comprises a gas storage tank and a compressor unit which are connected with each other, the cooling water supply unit comprises a first high-pressure water pump and a first heat exchanger which are connected with each other, the heating unit comprises a second high-pressure water pump and a second heat exchanger which are connected with each other, and the energy recovery unit comprises a gas-liquid separator and an expansion unit which are connected with each other.

Preferably, the reaction kettles are at least one, the non-corrosive gas supply unit is connected with the non-corrosive gas inlets of the reaction kettles through pipelines and is communicated with the high-pressure cavity, the heating unit is connected with the water-oxygen mixed fluid inlets of the reaction kettles through pipelines and the oxygen supply unit after converging, and is communicated with the reaction cavity, the cooling water supply unit is connected with the temperature control water inlets of the reaction kettles through pipelines, and the energy recovery unit is connected with the kettle body outlets of the reaction kettles through pipelines.

Preferably, the water-oxygen mixed fluid inlet, the non-corrosive gas inlet, the temperature control water inlet and the kettle body outlet are all provided with control valves.

Preferably, the heating unit comprises a fourth guide pipe and a heating kettle, the heating kettle is a heating kettle with a cavity inside, a water inlet and a water outlet are arranged on the heating kettle, and the fourth guide pipe is connected with the water inlet and stretches into the middle of the inner cavity of the heating kettle.

Preferably, the heating kettle further comprises a first-stage baffle plate, wherein a first-stage mixing cavity is formed between the inner wall of the first-stage baffle plate and the bottom of the heating kettle, one end of the fourth flow guide pipe extends into the water inlet and is arranged in the first-stage mixing cavity, a plurality of first flow guide holes are formed in the first-stage baffle plate at the position of one end connected with the heating kettle, the first-stage mixing cavity is communicated with the inner cavity of the heating kettle through the first flow guide holes, and a heating sleeve for heating the heating kettle is arranged on the outer side wall of the heating kettle;

The heating kettle is characterized by further comprising a secondary baffle plate, wherein the secondary baffle plate is arranged on the periphery of the primary baffle plate, a secondary mixing cavity is formed by the inner wall of the secondary baffle plate, the outer wall of the primary baffle plate and the bottom of the heating kettle, a tertiary mixing cavity is formed between the inner wall of the heating kettle and the outer wall of the secondary baffle plate, the primary mixing cavity is communicated with the secondary mixing cavity through the first diversion hole, a second diversion hole is formed in one end, far away from the bottom of the heating kettle, of the secondary baffle plate, and the secondary mixing cavity is communicated with the tertiary mixing cavity through the second diversion hole.

Preferably, at least one of the primary baffles and at least one of the secondary baffles are arranged in a crossing manner, and a plurality of the primary baffles and a plurality of the secondary baffles are arranged.

Preferably, one end of the fourth flow guiding pipe, which is arranged in the primary mixing cavity, is provided with a plurality of third flow guiding holes, and the fourth flow guiding pipe is communicated with the primary mixing cavity through the third flow guiding holes.

By adopting the design scheme, the invention has the beneficial effects that: introducing supercritical water and oxygen into a reaction cavity of the lining kettle body through a flow guide pipe, firstly oxidizing a bottom raw material, gradually forming a self-propagating reaction of a candle pile from bottom to top, and controlling the reaction rate and the decomposition rate by controlling the injection rate of the supercritical water and the oxygen; the high-pressure environment formed by non-corrosive gas is adopted to replace the water environment in the traditional supercritical water system, and the lining kettle body is combined to perform double isolation on corrosive medium, so that the corrosion of the external metal pressure-bearing kettle body surface on the corrosive medium is prevented to the greatest extent, the service life of equipment is prolonged, and the operation safety of the equipment is ensured; the intermittent reaction replaces the continuous reaction, so that the treatment of the solid waste raw materials with high solid content is realized, inorganic salt is not required to be discharged in the reaction process, the lining of the reaction kettle is completely taken out after the reaction is finished, the recycling of the inorganic salt can be effectively finished, and the salt accumulation and blockage are effectively prevented.

Drawings

FIG. 1 is a schematic structural diagram of a reaction kettle in the invention;

FIG. 2 is an exploded view of the reactor of the present invention;

FIG. 3 is a schematic diagram of the present invention;

FIG. 4 is a schematic structural view of a heating kettle in the invention;

FIG. 5 is a schematic diagram of a heating unit of the present invention;

In the figure: the reaction kettle 1, the pressure-bearing kettle body 11, the first kettle body 111, the first kettle cover 112, the first through hole 113, the second through hole 114, the lining kettle body 12, the second kettle body 121, the second kettle cover 122, the third through hole 123, the high-pressure cavity 13, the reaction cavity 14, the flow guide 15, the first flow guide 151, the second flow guide 152, the third flow guide 153, the water-oxygen mixed fluid inlet 161, the non-corrosive gas inlet 162, the temperature-control water inlet 163, the kettle body outlet 164, the oxygen supply unit 2, the liquid oxygen storage tank 21, the liquid oxygen pump 22, the oxygen heat exchanger 23, the non-corrosive gas supply unit 3, the gas storage tank 31, the compressor unit 32, the cooling water supply unit 4, the first high-pressure water pump 41, the first heat exchanger 42, the heating unit 5, the second high-pressure water pump 51, the second heat exchanger 52, the fourth flow guide 53, the third flow guide 531, the heating kettle 54, the water inlet 541, the water outlet 542, the third mixing cavity 543, the first baffle plate 55, the first mixing cavity 551, the first baffle plate 552, the second baffle plate 561, the second mixing cavity 561, the second baffle plate 62, the second flow guide unit 62, the energy recovery unit 6, the expansion valve 61 and the expansion unit.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 to 5:

A supercritical water self-propagating reaction system comprises a reaction kettle 1, an oxygen supply unit 2, a non-corrosive gas supply unit 3, a cooling water supply unit 4, a heating unit 5 and an energy recovery unit 6.

The reaction kettle 1 comprises a pressure-bearing kettle body 11 and a lining kettle body 12 arranged in the pressure-bearing kettle body 11, wherein the pressure-bearing kettle body 11 and the lining kettle body 12 are both closed kettle bodies, and the pressure-bearing kettle body and the lining kettle body 12 form a back-shaped structure. An annular gap is formed between the inner wall of the pressure-bearing kettle body 11 and the outer wall of the lining kettle body 12, a closed high-pressure cavity 13 is formed, and a closed reaction cavity 14 is formed in the inner cavity of the lining kettle body 12. Preferably, the lining kettle body 12 is a rigid lining kettle body 12, the rigid lining kettle body 12 is used for replacing the periphery of the fluid, the reaction area is effectively controlled within the fixed range of the reaction cavity 14, highly corrosive substances are prevented from directly contacting the pressure-bearing kettle body 11, and the service life of the pressure-bearing kettle body 11 is prolonged. The inner liner tank 12 is not required to be pressurized by the internal and external communication, and thus can be made into a thin-walled type and consumable part.

The pressure-bearing kettle body 11 is provided with a water-oxygen mixed fluid inlet 161, a non-corrosive gas inlet 162, a temperature-control water inlet 163 and a kettle body outlet 164 which are communicated with the high-pressure cavity 13 and the outside, and the reaction cavity 14 is communicated with the water-oxygen mixed fluid inlet 161 through a flow guide pipe 15. A high pressure non-corrosive gas (air or nitrogen, etc.) is introduced into the non-corrosive gas inlet 162 before the reaction, forming a high pressure environment, causing the supercritical water and oxygen mixture to enter the reaction chamber 14 and then rapidly reach the reaction conditions. The high pressure gas is interposed between the liner tank body 12 and the autoclave body 11 in the high pressure chamber 13, further reducing the chance of corrosive substances flowing into the autoclave body 11 to contact it. Compared with the traditional water environment, the high-pressure gas has low density and low specific heat, so the lower thermal inertia can improve the starting speed of the whole reaction.

Further, the pressure-bearing kettle body 11 comprises a first kettle body 111 and a first kettle cover 112 which are detachably connected, and the lining kettle body 12 comprises a second kettle body 121 and a second kettle cover 122 which are detachably connected. It should be noted that, the detachable connection in this embodiment may be a detachable connection that is conventionally used in the market, so long as a closed environment can be formed in the pressure-bearing kettle body 11 and the lining kettle body 12, which will not be described in detail herein.

The intermittent supercritical water oxidation reactor can reduce the constraint of the treated object on the shape and size, and is more suitable for treating urban solid wastes with complex structures and various types. Unlike continuous structure, batch reactors have frequent opening of the kettle for filling and taking of materials. However, in the traditional intermittent reactor structure, the kettle cover is not only connected and sealed with the kettle body, but also is connected with an external pipeline in order to facilitate design, and the connection of a plurality of positions reduces the opening speed of the kettle cover, so that the utilization rate of equipment is directly limited.

In order to avoid the influence of active engagement parts between the first kettle body 111 and the first kettle cover 112 and between the second kettle body 121 and the second kettle cover 122 as much as possible, the embodiment adopts a thimble type interface design and divides the conduit 15 into three-stage structures.

Specifically, the flow guiding tube 15 includes a first flow guiding tube 151, a second flow guiding tube 152 and a third flow guiding tube 153, which are sequentially communicated from end to end, the first flow guiding tube 151 is disposed on the first kettle body 111, the second flow guiding tube 152 is disposed on the first kettle cover 112, the third flow guiding tube 153 is disposed on the second kettle cover 122, one end of the first flow guiding tube 151 far away from the second flow guiding tube 152 is connected with the water-oxygen mixed fluid inlet 161, and one end of the third flow guiding tube 153 far away from the second flow guiding tube 152 is disposed in the reaction cavity 14.

Further, the first flow guiding tube 151 is an L-shaped tube, the second flow guiding tube 152 is a U-shaped tube, the third flow guiding tube 153 is a straight tube, the first kettle cover 112 is provided with a first through hole 113 and a second through hole 114 for the two ends of the second flow guiding tube 152 to pass through, the second kettle cover 122 is provided with a third through hole 123 for the third flow guiding tube 153 to pass through, and the axis of the first through hole 113 is parallel to the axis of the second through hole 114. When the first kettle body 111, the first kettle cover 112, the second kettle body 121 and the second kettle cover 122 are both closed, the axis of the second through hole 114 and the axis of the third through hole 123 are coincident, one end of the second flow guiding pipe 152 is penetrated in the first through hole 113 and is communicated with the first flow guiding pipe 151, the other end of the second flow guiding pipe 152 is penetrated in the second through hole 114 and is communicated with the third flow guiding pipe 153, the third flow guiding pipe 153 is penetrated on the third through hole 123, and one end far away from the second flow guiding pipe 152 extends to the bottom of the reaction cavity 14. The third flow guide pipe 153 is placed on the second kettle cover 122 and extends into the reaction cavity 14, and the pressure in the tank is balanced by means of the pressure in the reaction cavity 14, so that the sealing requirement on the joint is greatly weakened. Meanwhile, the first flow guide pipe 151 is fixedly arranged on the first kettle body 111, and the second flow guide pipe 152 is fixedly arranged on the first kettle cover 112, so that the first kettle cover 112 can be opened and closed better, and the second kettle cover 122 can be opened and closed better. Under the condition that the reasonable distribution of the guide pipes 15 can be ensured, the size of the whole pressure-bearing kettle body 11 is reduced, the sealing requirement on the joint is weakened, the opening rate of the kettle cover is improved, and the manufacturing cost of equipment is reduced. It should be noted that, the third flow guide tube 153 introduces supercritical water and oxygen into the bottom of the reaction cavity 14, the oxygen oxidizes the solid waste at the bottom, the oxidation rate and the decomposition amount of the solid waste are controlled by the oxygen concentration, and along with the oxidation of the bottom reactant, the oxygen is gradually transferred upwards to form a self-propagating reaction of a candle pile type from bottom to top, so that the raw materials with high solid content can be treated, and the controllability of the reaction rate and the decomposition rate is improved. In the reaction process, inorganic salt is automatically deposited at the bottom of the lining kettle body 12, after the reaction is completed, the first kettle cover 112 and the second kettle cover 122 can be opened, the inorganic salt in the lining kettle body 12 is recycled, the inorganic salt is not required to be discharged in the reaction process, and the risk of inorganic salt deposition blockage is eliminated.

Further, when the reaction vessel 1 is plural, the plural reaction vessels 1 may share auxiliary units such as the oxygen supply unit 2, the non-corrosive gas supply unit 3, the cooling water supply unit 4, the heating unit 5, and the energy recovery unit 6 through the split piping. The non-corrosive gas supply unit 3 is connected with the non-corrosive gas inlet 162 of each reaction kettle 1 through a pipeline and is communicated with the high-pressure cavity 13, the heating unit 5 is connected with the water-oxygen mixed fluid inlet 161 of each reaction kettle 1 through a pipeline and the oxygen supply unit 2 after converging and is communicated with the reaction cavity 14, the cooling water supply unit 4 is connected with the temperature control water inlet 163 of each reaction kettle 1 through a pipeline and is communicated with the high-pressure cavity 13, and the energy recovery unit 6 is connected with the kettle body outlet 164 of each reaction kettle 1 through a pipeline. The reaction heat is taken away by supercritical water, and the rest part is taken away by cooling water of the cooling water supply unit 4, so that the effective operation of the lining kettle body 12 is ensured.

The oxygen supply unit 2 includes a liquid oxygen tank 21, a liquid oxygen pump 22 and an oxygen heat exchanger 23 connected to each other, the non-corrosive gas supply unit 3 includes a gas tank 31 and a compressor unit 32 connected to each other, the cooling water supply unit 4 includes a first high-pressure water pump 41 and a first heat exchanger 42 connected to each other, and the energy recovery unit 6 includes a gas-liquid separator 61 and an expansion unit 62 connected to each other. The reaction heat in the lining kettle body 12 is taken away by spraying the outer wall of the lining kettle body 12 or immersing the cooling water, excessive temperature disturbance cannot be caused to the inside of the lining kettle body 12, the reaction rate of raw materials is guaranteed, water vapor and reaction gas products are discharged out of the reaction kettle 1 together, the expansion unit 62 is subjected to work recovery energy, the saved exhaust steam can continuously recover waste heat, and useful gases (hydrogen, methane and the like) in the waste heat are recovered and utilized.

The invention further provides a cross-critical zone heating unit 5, which specifically comprises a second high-pressure water pump 51, a second heat exchanger 52, a fourth flow guide pipe 53 and a heating kettle 54, wherein the heating kettle 54 is a heating kettle 54 with a cavity inside, a water inlet 541 and a water outlet 542 are arranged on the heating kettle 54, and the fourth flow guide pipe 53 is connected with the water inlet 541 and extends into the middle of the inner cavity of the heating kettle 54. Preferably, the outer side wall of the heating kettle 54 is provided with a heating jacket (not shown) for heating the heating kettle 54 and sleeved on the outer side wall of the heating kettle 54.

Further, at least one first-stage baffle plate 55 is arranged in the heating kettle 54, one end of the first-stage baffle plate 55 is connected with one side of the heating kettle 54, which is provided with a water inlet 541, a first-stage mixing cavity 551 is formed between the inner wall of the first-stage baffle plate 55 and the bottom of the heating kettle 54, one end of the fourth flow guide pipe 53 extends into the water inlet 541 and is arranged in the first-stage mixing cavity 551, a plurality of first flow guide holes 552 are formed at one end of the first-stage baffle plate 55, which is connected with the heating kettle 54, and the first-stage mixing cavity 551 is communicated with the inner cavity of the heating kettle 54 through the first flow guide holes 552.

Further, at least one secondary baffle plate 56 is further arranged in the heating kettle 54, the secondary baffle plate 56 is arranged on the periphery of the primary baffle plate 55, one end of the secondary baffle plate 56 is connected with the bottom of the heating kettle 54, a secondary mixing cavity 561 is formed among the inner wall of the secondary baffle plate 56, the outer wall of the primary baffle plate 55 and the bottom of the heating kettle 54, a tertiary mixing cavity 543 is formed between the inner wall of the heating kettle 54 and the outer wall of the secondary baffle plate 56, the primary mixing cavity 551 is communicated with the secondary mixing cavity 561 through a first diversion hole 552, a second diversion hole 562 is arranged at one end of the secondary baffle plate 56 far away from the bottom of the heating kettle 54, and the secondary mixing cavity 561 is communicated with the tertiary mixing cavity 543 through the second diversion hole 562. It should be noted that, when there are a plurality of primary baffles 55 and secondary baffles 56, the primary baffles 55 and the secondary baffles 56 are disposed in a crossing manner, and the secondary baffles 56 are disposed at the periphery of the adjacent primary baffles 55 all the time.

Preferably, the primary baffle 55 and the secondary baffle 56 are both corrosion resistant baffles, and the heating kettle 54 is a metal heating kettle 54. Separating the cooling water flowing out of the fourth draft tube 53 from the heating kettle 54 by the primary baffle 55 and the secondary baffle 56 effectively overcomes the problem of corrosion of the heating kettle 54, i.e., the heating kettle 54 suffering from corrosion is not subjected to pressure.

Further, a plurality of third diversion holes 531 are arranged at one end of the fourth diversion pipe 53 arranged in the first-stage mixing cavity 551, and the fourth diversion pipe 53 is communicated with the first-stage mixing cavity 551 through the third diversion holes 531. The stroke of working medium in the heating kettle 54 with limited volume can be increased by adjusting the length of the fourth flow guide pipe 53, the flow distribution structure of the third flow guide hole 531 and the like, so that the uniformity of flow distribution and heating is improved, and the large-temperature area crossing of supercritical fluid in a limited space is ensured.

Further, a plurality of temperature measuring points (not shown in the figure) are arranged on the water outlet 542 and the side wall of the heating kettle 54. The temperature measurement point of the water outlet 542 is to ensure that the temperature of the water outlet 542 is higher than the quasi-critical temperature, and the temperature measurement point of the side wall is to ensure that the near-wall fluid is also higher than the quasi-critical temperature.

The fourth flow guide pipe 53 is connected with the second heat exchanger 52, the second heat exchanger 52 heats the normal temperature medium to a preset temperature, and flows into the primary mixing cavity 551, the heating unit heats the heating kettle 54 for the second time and exchanges heat with the medium, and the preset temperature is higher than the supercritical temperature of the reaction liquid in the heating kettle 54.

The working procedure of the heating unit 5 of the present invention is: the normal temperature water is heated to a working condition lower than a critical area through a conventional second heat exchanger 52, the corrosiveness of the water in the temperature area is small, the water in the supercritical high-low temperature mixed heating kettle 54 is heated again, the temperature of the water in the kettle is controlled by a temperature controller all the time after the water in the kettle passes through the critical area only when being heated for the first time and is maintained in an area higher than the target temperature by 20-50 ℃, the preheated water is sent into the middle part of the high-pressure kettle through a fourth guide pipe 53, the water with the lower temperature is surrounded by the high temperature water and is diffused after being fused rapidly, and an inclined temperature layer is formed in the supercritical high-low temperature mixed heating kettle 54. Before the injected cold water reaches the heating kettle 54, the temperature of the mixed cold and hot fluid is higher than the temperature of the quasi-critical zone, so that the quasi-critical temperature zone is crossed.

The cross-critical zone heating unit 5 provided by the patent is not only limited to supercritical water cross-critical zone heating, but also can be used for heating/cooling other working media in a cross-temperature zone, and an inclined temperature layer is formed by mixing cold and hot fluid, so that the contact of an external wall surface and an undesirable working medium in a temperature zone is avoided. The heating kettle 54 can also serve as a buffer tank, and when parameters such as the flow rate, the pressure and the like of the working medium fluctuate, the influence of fluctuation of the operating parameters on the outlet temperature is counteracted by depending on the heat capacity of the working medium.

Further, control valves 7 are arranged at the water-oxygen mixed fluid inlet 161, the non-corrosive gas inlet 162, the temperature control water inlet 163 and the kettle outlet 164. Through detection and feedback of the internal pressure, a strong and robust valve 7 control strategy is developed to control the internal pressure of the reaction kettle 1 and discharge the product. From the safety point of view, the three-dimensional combination of valve 7 control, temperature control and oxygen concentration control is considered, so that the problem of pressure surge caused by fluctuation of the organic matter content of the raw materials due to the complexity of urban solid waste is effectively solved.

By adopting the design scheme, the invention has the beneficial effects that:

1. The intermittent reaction flow reconstruction is adopted, and the raw materials are directly filled into the lining kettle body 12 before the reaction starts, so that the treatment of the raw materials with high solid content can be realized;

2. introducing supercritical water and oxygen into the reaction cavity 14 of the lining kettle body 12 through the flow guide pipe 15, firstly oxidizing the bottom raw material to gradually form a self-propagating reaction of a candle pile from bottom to top, and controlling the reaction rate and the decomposition rate by controlling the injection rate of the supercritical water and the oxygen;

3. the high-pressure environment formed by non-corrosive gas is adopted to replace the water environment in the traditional supercritical water system, and the lining kettle body 12 is combined to perform double isolation on corrosive medium, so that the corrosion of the corrosive medium received by the surface of the external metal pressure-bearing kettle body 11 is prevented to the greatest extent, the service life of equipment is prolonged, and the operation safety of the equipment is ensured;

4. The intermittent supercritical water oxidation reactor can reduce the constraint of the treated object on the shape and size, and is more suitable for treating urban solid wastes with complex structures and various types.

5. The high-low temperature fluid mixing heating kettle 54 is designed, a stable inclined temperature layer is formed inside, the crossing of a working medium to a temperature zone is realized, and the inner wall of an external kettle body is prevented from being contacted with the working medium in a critical zone;

6. Optimizing the inclined temperature layer by means of the length of the fourth guide pipe 53, the flow distribution structures of the first guide holes and the third guide holes, the primary baffle plate, the secondary baffle plate and the like, so that the large temperature area crossing of the supercritical fluid is realized in a limited space;

7. the temperature of the outlet can be regulated by measuring the temperature of the inner wall surface of the heating kettle 54 and the temperature of the outlet of the heating kettle 54 and controlling the heating power of the second heat exchanger 52, the heating power of the heating kettle 54 and the flow rate of the working medium, so that the working medium flowing out of the heating kettle 54 can be ensured to cross the critical area, the development condition of an inclined temperature layer can be controlled, and the metal wall surface is ensured not to be contacted with the working medium in the critical area;

8. The heating kettle 54 can also serve as a buffer tank, when parameters such as the flow rate and the pressure of the working medium fluctuate, the influence of the fluctuation of the operation parameters on the outlet temperature is counteracted by depending on the heat capacity of the working medium, so that the operation of the heating system is more stable.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A supercritical water self-propagating reaction system is characterized in that: including reation kettle and heating unit, reation kettle includes the pressure-bearing cauldron body and sets up the inside lining cauldron body of the pressure-bearing cauldron body, the pressure-bearing cauldron body with the lining cauldron body is the closed cauldron body, the inner wall of the pressure-bearing cauldron body with form the annular space between the outer wall of the lining cauldron body to constitute a confined high-pressure chamber, the inner chamber of the lining cauldron body forms a confined reaction chamber, be provided with water oxygen mixed fluid entry and intercommunication on the pressure-bearing cauldron body the high-pressure chamber is with the non-corrosive gas entry, the control by temperature change water entry of external world and cauldron body export, the reaction chamber through a honeycomb duct with water oxygen mixed fluid entry is linked together, the heating unit through the pipeline with water oxygen mixed fluid entry is linked together.

2. The supercritical water self-propagating reaction system of claim 1, wherein: the pressure-bearing kettle body comprises a first kettle body and a first kettle cover which are detachably connected, and the lining kettle body comprises a second kettle body and a second kettle cover which are detachably connected.

3. The supercritical water self-propagating reaction system of claim 2, wherein: the honeycomb duct includes first honeycomb duct, second honeycomb duct and the third honeycomb duct that the head and the tail are linked together in proper order, first honeycomb duct sets up on the first cauldron body, the second honeycomb duct sets up first cauldron is covered, the third honeycomb duct sets up on the second cauldron is covered, first honeycomb duct keep away from the one end of second honeycomb duct with water oxygen mixed fluid entry is connected, the third honeycomb duct is kept away from the one end setting of second honeycomb duct is in the reaction chamber.

4. A supercritical water self-propagating reaction system according to claim 3, wherein: the first honeycomb duct is L type pipe, the second honeycomb duct is U type pipe, the third honeycomb duct is the straight tube, first kettle cover is provided with the confession the both ends of second honeycomb duct are worn to put first through-hole and second through-hole, the second kettle cover is provided with the confession the third through-hole that the third honeycomb duct worn to put, the axis of second through-hole with the axis of third through-hole coincides mutually, the one end of second honeycomb duct wear to establish in the first through-hole and with first honeycomb duct is linked together, the other end of second honeycomb duct wear to establish in the second through-hole and with the third honeycomb duct is linked together, the third honeycomb duct wear to establish on the third through-hole.

5. The supercritical water self-propagating reaction system of claim 1, wherein: the device comprises a kettle body, a high-pressure cavity, a heating unit, a water-oxygen mixed fluid inlet, a reaction cavity, a pipeline, a non-corrosive gas supply unit, a cooling water supply unit and an energy recovery unit, wherein the non-corrosive gas supply unit is connected with the non-corrosive gas inlet through the pipeline and is communicated with the high-pressure cavity, the heating unit is connected with the water-oxygen mixed fluid inlet and is communicated with the reaction cavity after being converged by the pipeline and the oxygen supply unit, the cooling water supply unit is connected with the temperature-control water inlet through the pipeline and is communicated with the high-pressure cavity, and the energy recovery unit is connected with the kettle body outlet through the pipeline.

6. The supercritical water self-propagating reaction system of claim 5, wherein: the oxygen supply unit comprises a liquid oxygen storage tank, a liquid oxygen pump and an oxygen heat exchanger which are connected with each other, the non-corrosive gas supply unit comprises a gas storage tank and a compressor unit which are connected with each other, the cooling water supply unit comprises a first high-pressure water pump and a first heat exchanger which are connected with each other, the heating unit comprises a second high-pressure water pump and a second heat exchanger which are connected with each other, and the energy recovery unit comprises a gas-liquid separator and an expansion unit which are connected with each other.

7. The supercritical water self-propagating reaction system of claim 5, wherein: the reaction kettles are at least one, the non-corrosive gas supply unit is connected with the non-corrosive gas inlets of the reaction kettles through pipelines and is communicated with the high-pressure cavity, the heating unit is connected with the water-oxygen mixed fluid inlets of the reaction kettles through pipelines and the oxygen supply unit after converging, the cooling water supply unit is connected with the temperature control water inlets of the reaction kettles through pipelines, and the energy recovery unit is connected with the kettle body outlets of the reaction kettles through pipelines.

8. The supercritical water self-propagating reaction system of claim 1, wherein: the water-oxygen mixed fluid inlet, the non-corrosive gas inlet, the temperature control water inlet and the kettle body outlet are all provided with control valves.

9. The supercritical water self-propagating reaction system of claim 1, wherein: the heating unit comprises a fourth guide pipe and a heating kettle, wherein the heating kettle is a heating kettle with a cavity inside, a water inlet and a water outlet are formed in the heating kettle, and the fourth guide pipe is connected with the water inlet and stretches into the middle of the cavity of the heating kettle.

10. The supercritical water self-propagating reaction system of claim 9, wherein: the heating kettle comprises a water inlet, a water outlet, a heating kettle, a first-stage baffle plate, a second-stage baffle plate, a first-stage mixing cavity, a second-stage flow guide pipe, a third-stage flow guide pipe, a fourth-stage flow guide pipe and a heating kettle, wherein the water inlet is formed at the bottom of the heating kettle;

The heating kettle is characterized by further comprising a secondary baffle plate, wherein the secondary baffle plate is arranged on the periphery of the primary baffle plate, a secondary mixing cavity is formed by the inner wall of the secondary baffle plate, the outer wall of the primary baffle plate and the bottom of the heating kettle, a tertiary mixing cavity is formed between the inner wall of the heating kettle and the outer wall of the secondary baffle plate, the primary mixing cavity is communicated with the secondary mixing cavity through the first diversion hole, a second diversion hole is formed in one end, far away from the bottom of the heating kettle, of the secondary baffle plate, and the secondary mixing cavity is communicated with the tertiary mixing cavity through the second diversion hole.