Oil-containing sludge hydro-thermal treatment energy efficient utilization system and operation method thereof

Abstract

The invention relates to an oil-containing sludge hydro-thermal treatment energy efficient utilization system and an operation method thereof, and the system comprises a preheating fluidization part which is used for preheating a fluidization material; the steam heating part is used for heating the materials and participating in the hydrothermal reaction; the steam heating part is used for supplying high-temperature steam to the hydrothermal reaction part so as to carry out material heating and hydrothermal reaction, and flash evaporation is carried out after the hydrothermal reaction; the condensing medium flows into the steam heating part after being heated; the gas from the preheating fluidization part is cooled and condensed to form low-temperature flash condensate; the flash tank is used for mixing to form a flash destabilized mixture; and the centrifugal separation part is used for centrifugally separating the flash destabilized mixture from the flash tank. The heat load and the cooling load of system operation are reduced, and energy conservation and consumption reduction are achieved; and the low-temperature flash evaporation condensate is mixed with the materials in the flash evaporation tank, so that the oil content of the residual solid phase after centrifugal separation is further reduced, the volatilization of light petroleum components in the condensate is reduced, and the safety and pollution risks are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical environmental protection, and in particular to an energy efficient utilization system for hydrothermal treatment of oily sludge and an operation method thereof. Background Art

[0002] Oily sludge is a solid waste containing mineral oil generated during oil and gas drilling, gathering, transportation, storage, processing and oily wastewater treatment. It is divided into oily drilling mud, oil-based drill cuttings, ground oil sludge, oil tank sludge, oily scum sludge, etc. Oily drilling mud and oily scum sludge are a high-liquid (oil + water) homogeneous multiphase emulsion system, and its dehydration and drying is the bottleneck of subsequent treatment and disposal. Aged oil is a complex and stable water-containing oil slurry or oil-containing emulsion generated in crude oil gathering, storage, sewage treatment and petroleum and petrochemical production. Its stable state increases the processing cost and difficulty of the existing crude oil processing system. It not only occupies a large amount of storage space, but also affects the quality of external oil, interferes with the operation of the electric dehydration device, and causes equipment corrosion and scaling. How to economically and efficiently treat aged oil has become an urgent problem to be solved in the petroleum industry.

[0003] The hydrothermal treatment of materials such as oily sludge and aged oil is a process of flash evaporation after heating the materials under certain temperature and pressure conditions, breaking the flocs, cracking the macromolecular organic matter and dissolving some solids through a series of physical and chemical reactions, achieving conditioning, destabilization, dehydration and oil recovery. The hydrothermal treatment of oily sludge consumes a lot of energy, which increases the treatment cost. Therefore, energy saving and consumption reduction is one of the effective measures to promote its application.

[0004] There are some waste heat recovery technologies for energy saving and consumption reduction in the prior art, such as CN202211247216.9 a heat exchanger energy saver, an energy-saving and cooling system and its operation method, CN202210127775.X an energy-saving and emission-reduction type natural gas industrial furnace and energy-saving and emission-reduction method, CN201911069606.X a waste heat recovery energy-saving and environmental protection equipment with high-efficiency energy-saving function, CN201110065706.2 a device for waste heat recovery in waste gas and waste liquid treatment, CN201610022001.5 a high-efficiency waste heat recovery and comprehensive utilization system.

[0005] The above technologies can achieve energy saving and consumption reduction of the corresponding systems, but there is no report on how to improve the overall energy efficiency of the system and make efficient and comprehensive use of them.

[0006] Therefore, the inventors, relying on their many years of experience and practice in related industries, have proposed an energy efficient utilization system for hydrothermal treatment of oily sludge and an operation method thereof, so as to improve the efficient and comprehensive utilization of the overall energy efficiency of the system. Summary of the invention

[0007] The purpose of the present invention is to provide an energy efficient utilization system for hydrothermal treatment of oily sludge and an operation method thereof, which reduces the heat load and cooling load of the system operation and achieves energy saving and consumption reduction; the mixing of low-temperature flash condensate with the material in the flash tank helps to further reduce the oil content of the remaining solid phase after centrifugal separation and reduce the volatilization of light petroleum components in the condensate, thereby reducing safety and pollution risks.

[0008] The object of the present invention is achieved by providing an energy efficient utilization system for hydrothermal treatment of oily sludge, comprising:

[0009] Preheating fluidizing section, used for preheating fluidized materials;

[0010] Steam heating part, used to heat the materials and participate in the hydrothermal reaction;

[0011] A hydrothermal reaction section, wherein the material inlet is connected to the material outlet of the preheating fluidization section, and the gas outlet of the steam heating section is connected to the gas inlet of the hydrothermal reaction section. The steam heating section supplies high-temperature steam to the hydrothermal reaction section to perform material heating and hydrothermal reaction, and flash evaporation is performed after the hydrothermal reaction;

[0012] The flash heat recovery section is used to recover the flash heat after the hydrothermal reaction, and reuse the flash heat for the hydrothermal reaction of the material in the hydrothermal reaction section; and / or, the gas outlet of the hydrothermal reaction section is connected to the preheating fluidized section, and the gas flowing out of the hydrothermal reaction section heats the material in the preheating fluidized section; and / or, the flash heat is recycled and transported to the condensation heat exchange section;

[0013] A condensation heat exchange section, wherein the gas inlet is connected to the gas outlet of the preheating fluidization section, and a condensing medium flows through the condensing heat exchange section. The condensing medium is heated by the gas from the preheating fluidization section and then flows into the steam heating section; the gas from the preheating fluidization section is cooled and condensed by the condensing medium to form a low-temperature flash condensate;

[0014] A flash tank connected to the material outlet of the hydrothermal reaction part and the condensation heat exchange part, and used for mixing the material from the hydrothermal reaction part and the low-temperature flash condensate to form a flash destabilized mixed material;

[0015] The centrifugal separation part is connected to the flash tank to centrifugally separate the flash destabilized mixed material from the flash tank.

[0016] In a preferred embodiment of the present invention, the condensing heat exchange section includes a condensing heat exchanger and a chiller, a first heat exchange channel and a second heat exchange channel are arranged in the condensing heat exchanger, a gas outlet of the preheating fluidizing section is connected to the inlet of the first heat exchange channel, and the outlet of the first heat exchange channel is connected to the flash tank; the chiller is connected to the inlet of the second heat exchange channel to supply condensing medium, and the outlet of the second heat exchange channel is connected to the steam heating section.

[0017] In a preferred embodiment of the present invention, the hydrothermal reaction section includes at least three reactors, the gas inlet of one reactor is connected to the gas outlet of the steam heating section to form a heating reactor, and another adjacent reactor is connected to the heating reactor to form a heating reactor. Flash steam from the heating reactor is transported to the heating reactor to heat and equalize the pressure of the material inside it, and each reactor is alternately heated and equalized in pressure; the remaining gas after flash evaporation of the reactor flows to the preheating fluidized section through the gas outlet of the hydrothermal reaction section.

[0018] In a preferred embodiment of the present invention, valves are provided between adjacent reaction kettles.

[0019] In a preferred embodiment of the present invention, the preheating fluidizing section includes a raw material storage tank and a fluidizing tank, the material outlet of the raw material storage tank is connected to the material inlet of the fluidizing tank, and the material outlet of the fluidizing tank is connected to the material inlet of the hydrothermal reaction section; the flash steam heat recovery section includes a first flash steam branch and a second flash steam branch, the first flash steam branch is connected to the gas outlet of the hydrothermal reaction section and the gas inlet of the fluidizing tank, and the second flash steam branch is connected to the gas outlet of the fluidizing tank and the gas inlet of the raw material storage tank.

[0020] In a preferred embodiment of the present invention, a first coil is disposed in the fluidizing tank, an inlet of the first coil constitutes a gas inlet of the fluidizing tank, and an outlet of the first coil constitutes a gas outlet of the fluidizing tank.

[0021] In a preferred embodiment of the present invention, a second coil is provided on the outer wall of the raw material storage tank, the inlet of the second coil constitutes the gas inlet of the raw material storage tank, and the outlet of the second coil constitutes the gas outlet of the raw material storage tank.

[0022] The object of the present invention can also be achieved in this way. An operating method of an energy efficient utilization system for hydrothermal treatment of oily sludge comprises: a preheating fluidizing section supplies materials to a hydrothermal reaction section, a steam heating section supplies high-temperature steam to the hydrothermal reaction section, the materials in the hydrothermal reaction section undergo a hydrothermal reaction, flash evaporates after the reaction, the materials after the reaction are transported to a flash tank, the remaining gas after the flash evaporates is heated by a flash heat recovery section to heat the materials in the preheating fluidizing section, the gas flowing out of the preheating fluidizing section enters a condensation heat exchange section, exchanges heat with a condensing medium to cool and condense to form a low-temperature flash condensate, and the condensing medium is heated and flows into the steam heating section; the low-temperature flash condensate flows into the flash tank, and is mixed with the materials after the reaction to form a flash destabilization mixture; the flash destabilization mixture flows into a centrifugal separation section, and the flash destabilization mixture is centrifugally separated into an oil phase material, an aqueous phase material and a solid phase material.

[0023] In a preferred embodiment of the present invention, the hydrothermal reaction section includes multiple reactors, and the steam heating section supplies high-temperature steam of 230-300°C to a reactor in the hydrothermal reaction section. The material in one reactor is heated and hydrothermally reacted, and flash vaporization is performed after the reaction. The flash steam from one reactor heats the material in another reactor and equalizes the pressure. The multiple reactors exchange heat alternately in sequence, raising the temperature of the material from 90-95°C to 140-155°C, thereby completing the first-level waste heat utilization.

[0024] In a preferred embodiment of the present invention, the remaining gas after the flash evaporation of the reactor is used to heat the material in the fluidized tank of the preheating fluidized part, raising the temperature of the material from 40-50°C to 70-90°C, completing the secondary waste heat utilization.

[0025] In a preferred embodiment of the present invention, the tail gas after heating the fluidized tank flows to the raw material storage tank of the preheating fluidized part, raising the temperature of the original material to 40-50°C, completing the three-stage waste heat utilization.

[0026] In a preferred embodiment of the present invention, after heating the tank material, the exhaust gas enters the condensation heat exchange part, exchanges heat with the condensing medium to cool and condense to form a low-temperature flash condensate. The condensing medium is heated and flows into the steam heating part to complete the four-stage waste heat utilization.

[0027] In a preferred embodiment of the present invention, the low-temperature flash condensate is mixed with the reacted material in the flash tank, the material temperature is reduced to ≤80°C, and the low-temperature flash condensate and the reacted material in the flash tank are oil-oil extracted.

[0028] As described above, the energy efficient utilization system for hydrothermal treatment of oily sludge and the operation method thereof of the present invention have the following beneficial effects:

[0029] The present invention realizes the step-by-step utilization of energy by using the hydrothermal flash gas in the hydrothermal reaction part to perform step-by-step heat exchange on the material. The remaining flash steam after the material preheating heat exchange is condensed and heat exchanged in the condensation heat exchange part. The condensation medium in the condensation heat exchange part is heated up and used as the water in the heating part to realize multi-stage waste heat utilization and reduce the heat load. The gas from the preheating fluidization part is cooled and condensed to form a low-temperature flash condensate which flows back to the flash tank, and the material in the tank is cooled to reduce the consumption of cooling water required for the condensation of the material, thereby reducing the cooling load and realizing energy saving and consumption reduction. At the same time, the low-temperature flash condensate is mixed with the material in the flash tank to reduce the volatilization of oil and gas, and the light oil is mixed with the heavy oil in the flash tube to realize extraction and oil extraction, and finally the oil content of the remaining solid phase after centrifugation is reduced, the volatilization of the light petroleum component is reduced, and the safety and pollution risks are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0031] in:

[0032] Figure 1 : It is a schematic diagram of the energy efficient utilization system for hydrothermal treatment of oily sludge of the present invention.

[0033] In the figure:

[0034] 1. Raw material storage tank; 10. Original material; 11. Preheated storage tank material; 12. Exhaust gas after heating the raw material storage tank material;

[0035] 2. Fluidized tank; 21. Fluidized material; 22. Exhaust gas after heat exchange in the fluidized tank;

[0036] 3. Hydrothermal reaction section; 31. Reaction material; 32. Flash steam; 33. Residual gas after flash evaporation;

[0037] 4. Flash tank; 41. Flash destabilization of the mixture;

[0038] 5. Centrifugal separation section; 51. Oil phase material; 52. Water phase material; 53. Solid phase material;

[0039] 6. Steam boiler; 61. High temperature steam;

[0040] 7. Condensation heat exchanger; 71. Low-temperature flash condensate; 72. Tap water after heat exchange;

[0041] 8. Chiller; 81. Low-temperature tap water. DETAILED DESCRIPTION

[0042] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0043] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0045] like Figure 1 As shown, the present invention provides an energy efficient utilization system for hydrothermal treatment of oily sludge, comprising:

[0046] Preheating fluidizing section, used for preheating fluidized materials;

[0047] Steam heating unit, used to heat materials and participate in hydrothermal reactions; or to produce / provide high-temperature steam;

[0048] The hydrothermal reaction part has a material inlet connected to the material outlet of the preheating fluidization part, and a gas outlet of the steam heating part connected to the gas inlet of the hydrothermal reaction part. The steam heating part supplies high-temperature steam to the hydrothermal reaction part to perform material heating and hydrothermal reaction, and flash evaporation after the hydrothermal reaction;

[0049] The flash heat recovery section is used to recover the flash heat after the hydrothermal reaction, and reuse the flash heat for the hydrothermal reaction of the material in the hydrothermal reaction section; and / or, the gas outlet of the hydrothermal reaction section is connected to the preheating fluidized section, and the gas flowing out of the hydrothermal reaction section heats the material in the preheating fluidized section (raw material storage tank 1 and fluidized tank 2); and / or, the flash heat is recycled and transported to the condensation heat exchange section;

[0050] The gas inlet of the condensation heat exchange section is connected to the gas outlet of the preheating fluidization section. The condensation medium flows through the condensation heat exchange section. The condensation medium is heated by the gas from the preheating fluidization section and then flows into the steam heating section. The gas from the preheating fluidization section is cooled and condensed by the condensation medium to form a low-temperature flash condensate 71.

[0051] A flash tank (using existing technology) connected to the material outlet of the hydrothermal reaction part and the condensation heat exchange part, used to mix the material from the hydrothermal reaction part and the low-temperature flash condensate to form a flash destabilized mixed material 41;

[0052] The centrifugal separation section 5 (which can be made of existing technology) is connected to the flash tank to centrifugally separate the flash destabilized mixed material 41 from the flash tank.

[0053] The system includes material channels and fluid channels. Material channels: material outlet of preheating fluidization section → material inlet of hydrothermal reaction section → material outlet of hydrothermal reaction section → flash tank → centrifugal separation section. Fluid channels: gas outlet of steam heating section → gas inlet of hydrothermal reaction section → gas outlet of hydrothermal reaction section → flash heat recovery section → gas inlet of condensation heat exchange section → low-temperature flash condensate outlet of condensation heat exchange section → flash tank. High-temperature steam in steam heating section exchanges heat with materials at various levels through fluid channels to realize energy cascade utilization and multi-stage waste heat utilization, reduce the heat load and cooling load of system operation, and achieve energy saving and consumption reduction.

[0054] The present invention realizes the step-by-step utilization of energy by using the hydrothermal flash gas in the hydrothermal reaction part to perform step-by-step heat exchange on the material. The remaining flash steam after the material preheating heat exchange is condensed and heat exchanged in the condensation heat exchange part. The condensation medium in the condensation heat exchange part is heated up and used as the water in the heating part to realize multi-stage waste heat utilization and reduce the heat load. The gas from the preheating fluidization part is cooled and condensed to form a low-temperature flash condensate which flows back to the flash tank, and the material in the tank is cooled to reduce the consumption of cooling water required for the condensation of the material, thereby reducing the cooling load and realizing energy saving and consumption reduction. At the same time, the low-temperature flash condensate is mixed with the material in the flash tank to reduce the volatilization of oil and gas, and the light oil is mixed with the heavy oil in the flash tube to realize extraction and oil extraction, and finally the oil content of the remaining solid phase after centrifugation is reduced, the volatilization of the light petroleum component is reduced, and the safety and pollution risks are reduced.

[0055] Embodiment 1

[0056] like Figure 1 As shown, the condensation heat exchange part includes a condensation heat exchanger 7 and a chiller 8. The condensation heat exchanger 7 is provided with a first heat exchange channel and a second heat exchange channel. The gas outlet of the preheating fluidization part is connected to the inlet of the first heat exchange channel, and the outlet of the first heat exchange channel is connected to the flash tank 4. The chiller 8 is connected to the inlet of the second heat exchange channel to supply the condensation medium, and the outlet of the second heat exchange channel is connected to the steam heating part. The steam heating part adopts a steam boiler 6.

[0057] The chiller 8 delivers low-temperature tap water 81 to the second heat exchange channel of the condensing heat exchanger 7, and the low-temperature tap water constitutes the condensing medium. After heat exchange, the low-temperature tap water is heated and delivered to the steam boiler 6 as a hot water source for the steam boiler, reducing the heating load and realizing the four-level waste heat utilization.

[0058] Further, if Figure 1 As shown, the hydrothermal reaction part 3 includes at least three reactors (the existing technology can be used), the gas inlet of a reactor (3-A) is connected with the gas outlet of the steam heating part to form a heating reactor, and another adjacent reactor (3-B) is connected with the heating reactor to form a heating reactor, and the flash steam 32 of the heating reactor is transported to the heating reactor to heat the material inside the heating reactor and equalize the pressure; the flash heat recovery part includes a connecting pipeline between adjacent reactors;

[0059] The hydrothermal reaction unit 3 includes 3 to N reactors, and each reactor exchanges heat and equalizes pressure alternately in turn; after the heat exchange and equalization of pressure are completed, the temperature and pressure of the heating reactor and the heating reactor are kept consistent.

[0060] Furthermore, valves are arranged between adjacent reaction kettles.

[0061] After the heat exchange and pressure equalization are completed, the valve between the two kettles is closed, and the heating kettle continues to flash. The remaining gas 33 after flashing in the reaction kettle flows to the preheating fluidized part through the gas outlet of the hydrothermal reaction part.

[0062] Further, if Figure 1 As shown, the preheating fluidized part includes a raw material storage tank 1 and a fluidized tank 2 (the existing technology can be used), the material outlet of the raw material storage tank 1 is connected to the material inlet of the fluidized tank 2, and the material outlet of the fluidized tank 2 is connected to the material inlet of the hydrothermal reaction part 3; the flash steam heat recovery part includes a first flash steam branch and a second flash steam branch, the first flash steam branch is connected to the gas outlet of the hydrothermal reaction part 3 and the gas inlet of the fluidized tank 2, and the second flash steam branch is connected to the gas outlet of the fluidized tank 2 and the gas inlet of the raw material storage tank 1.

[0063] Furthermore, a first coil is provided in the fluidizing tank 2, the inlet of the first coil constitutes the gas inlet of the fluidizing tank, and the outlet of the first coil constitutes the gas outlet of the fluidizing tank.

[0064] Furthermore, a second coil is provided on the outer wall of the raw material storage tank 1, the inlet of the second coil constitutes the gas inlet of the raw material storage tank, and the outlet of the second coil constitutes the gas outlet of the raw material storage tank.

[0065] The steam heating part supplies high-temperature steam 61 to the hydrothermal reaction part, and the material in the hydrothermal reaction part undergoes a hydrothermal reaction, flashes after the reaction, and the material in the hydrothermal reaction part is heated, thereby realizing the first-level waste heat utilization of the high-temperature steam; the remaining gas 33 after the flash evaporation heats the material in the fluidized tank 2 through the first coil, thereby realizing the second-level waste heat utilization; the tail gas 22 after heat exchange with the fluidized tank preheats the original material through the second coil outside the raw material storage tank 1, thereby realizing the third-level waste heat utilization; the tail gas 12 after heating the material in the raw material storage tank flows to the condensing heat exchanger 7, and exchanges heat with the low-temperature tap water 81 supplied by the chiller 8. After the heat exchange, the temperature of the low-temperature tap water rises to form tap water 72 after heat exchange, which is transported to the steam boiler 6 as a hot water source for the steam boiler, thereby reducing the heating load and realizing the fourth-level waste heat utilization.

[0066] The original material 10 is transported and stored in the raw material storage tank 1. After the tail gas 22 of the fluidized tank is preheated by heat exchange, the storage tank material 11 is transported to the fluidized tank 2. The fluidized material 21 is transported to each reactor. The reacted material 31 of the hydrothermal reaction unit 3 is transported to the flash tank 4. The low-temperature flash condensate 71 from the condensation heat exchanger 7 is mixed and diluted with the reacted material 31, and the temperature of the flash destabilized mixed material 41 is reduced. The low-temperature flash condensate 71 can be directly cooled to the required temperature after mixing with the reacted material 31 (hot material in the flash tank), which greatly reduces the cooling load and further saves energy. The low-temperature flash condensate 71 can also be mixed with the reacted material 31 (hot material in the flash tank) to achieve oil-oil extraction, reducing the oil content of the remaining solid phase after centrifugation and the risk of volatilization of light petroleum components.

[0067] Embodiment 2

[0068] An operation method of an energy efficient utilization system for hydrothermal treatment of oily sludge comprises: a preheating fluidizing section supplies material to a hydrothermal reaction section 3, a steam heating section supplies high-temperature steam 61 to the hydrothermal reaction section 3, the material in the hydrothermal reaction section undergoes a hydrothermal reaction, flashes after the reaction, the material 31 after the reaction is transported to a flash tank 4, the remaining gas after the flash is heated by a flash heat recovery section to heat the material in the preheating fluidizing section, the gas flowing out of the preheating fluidizing section enters a condensation heat exchange section, exchanges heat with a condensing medium to cool and condense to form a low-temperature flash condensate 71, and the condensing medium is heated and flows into the steam heating section; the low-temperature flash condensate 71 flows into the flash tank 4, and is mixed with the material after the reaction 31 to form a flash destabilization mixture 41; the flash destabilization mixture 41 flows into a centrifugal separation section 5, and the flash destabilization mixture 41 is centrifugally separated into an oil phase material 51, a water phase material 52 and a solid phase material 53.

[0069] The specific steps include:

[0070] Step 1: The preheating fluidized part supplies materials to the hydrothermal reaction part 3, and the steam heating part (steam boiler 6) is started to heat and generate high-temperature steam 61. The steam heating part supplies high-temperature steam of 230-300°C to a reactor in the hydrothermal reaction part. The hydrothermal reaction part 3 includes at least 3 reactors. The high-temperature steam 61 heats the materials in the reactor (3-A) and supplies heat for the hydrothermal reaction. After the reaction, flash vaporization is performed. The reactor (3-A) constitutes a heating reactor. Another reactor (3-B) is connected to the heating reactor to form a heated reactor. The flash steam of the reactor (3-A) heats the materials in the other reactor (3-B) and equalizes the pressure. The reactors exchange heat and equalize the pressure alternately in turn. After the heat exchange and pressure equalization are completed, the temperature and pressure of the heating reactor and the heated reactor are kept consistent.

[0071] The material is heated from 90-95°C to 140-155°C to complete the primary waste heat utilization.

[0072] Step 2: After the heat exchange and pressure equalization are completed, the valve between the two kettles is closed, and the heating kettle continues to flash. The remaining gas 33 after flashing heats the material in the fluidized tank 2 through the first coil, raising the temperature of the material from 40-50°C to 70-90°C, completing the secondary waste heat utilization.

[0073] Step 3: The tail gas 22 after heat exchange in the fluidized tank is passed through the second coil outside the raw material storage tank 1 to preheat the original material, raising the temperature of the original material to 40-50° C., thereby realizing three-level waste heat utilization.

[0074] Step 4: After heating the material in the raw material storage tank, the tail gas 12 flows to the condensing heat exchanger 7, and exchanges heat with the low-temperature tap water 81 supplied by the chiller 8. After the heat exchange, the temperature of the low-temperature tap water rises to form heat-exchanged tap water 72, which is transported to the steam boiler 6 as a hot water source for the steam boiler, reducing the heating load and realizing four-level waste heat utilization.

[0075] The gas from the preheating fluidizing section (the tail gas 12 after heating the material in the raw material storage tank) is cooled and condensed by the condensing medium (low-temperature tap water 81) to form a low-temperature flash condensate 71.

[0076] Step 5: The low-temperature flash condensate 71 flows to the flash tank 4, and the reacted material 31 is transported from the hydrothermal reaction unit 3 to the flash tank 4. The low-temperature flash condensate 71 is mixed and diluted with the reacted material 31 to form a flash destabilized mixture 41, and the temperature of the flash destabilized mixture 41 is reduced to ≤80°C. After the low-temperature flash condensate 71 is mixed with the reacted material 31 (hot material in the flash tank), it can be directly cooled to the required temperature, which greatly reduces the cooling load and further saves energy.

[0077] The low-temperature flash condensate 71 is mixed with the post-reaction material 31 (hot material in the flash tank) to achieve oil-oil extraction, thereby reducing the oil content of the remaining solid phase after centrifugation and the risk of volatilization of light petroleum components.

[0078] Step 6: The flash evaporation destabilized mixed material 41 flows into the centrifugal separation part 5 , and the flash evaporation destabilized mixed material 41 is centrifugally separated into an oil phase material 51 , a water phase material 52 and a solid phase material 53 .

[0079] Embodiment 3

[0080] The oily sludge of a refinery has a water content of 78.94% and an oil content of 7.52%. This system is used to treat the oily sludge at a hydrothermal reaction temperature of 180°C, requiring 420kg / t of steam, which saves 41.23% energy compared with theoretical calculations.

[0081] Embodiment 4

[0082] The heavy oil sludge of a certain oil field has a water content of 77.43% and an oil content of 9.84%. This system is used to treat the hydrothermal reaction temperature at 210°C, requiring 490kg / t of steam for sludge, which saves 38.44% energy compared with theoretical calculations.

[0083] Embodiment 5

[0084] The heavy oil aging oil in a certain oil field has a water content of 44.83% and a solid content of 8.62%. This system is used to treat the hydrothermal reaction temperature of 210℃, requiring 464kg / t of steam, which saves 35.17% energy compared with theoretical calculations.

[0085] As described above, the energy efficient utilization system for hydrothermal treatment of oily sludge and the operation method thereof of the present invention have the following beneficial effects:

[0086] The present invention realizes the step-by-step utilization of energy by using the hydrothermal flash gas in the hydrothermal reaction part to perform step-by-step heat exchange on the material. The remaining flash steam after the material preheating heat exchange is condensed and heat exchanged in the condensation heat exchange part. The condensation medium in the condensation heat exchange part is heated up and used as the water in the heating part to realize multi-stage waste heat utilization and reduce the heat load. The gas from the preheating fluidization part is cooled and condensed to form a low-temperature flash condensate which flows back to the flash tank, and the material in the tank is cooled to reduce the consumption of cooling water required for the condensation of the material, thereby reducing the cooling load and realizing energy saving and consumption reduction. At the same time, the low-temperature flash condensate is mixed with the material in the flash tank to reduce the volatilization of oil and gas, and the light oil is mixed with the heavy oil in the flash tube to realize extraction and oil extraction, and finally the oil content of the remaining solid phase after centrifugation is reduced, the volatilization of the light petroleum component is reduced, and the safety and pollution risks are reduced.

[0087] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An energy efficient utilization system for hydrothermal treatment of oily sludge, characterized in that: include, Preheating fluidizing section, used for preheating fluidized materials; Steam heating section, used to heat materials and participate in hydrothermal reaction; A hydrothermal reaction section, wherein the material inlet is connected to the material outlet of the preheating fluidization section, and the gas outlet of the steam heating section is connected to the gas inlet of the hydrothermal reaction section. The steam heating section supplies high-temperature steam to the hydrothermal reaction section to perform material heating and hydrothermal reaction, and flash evaporation is performed after the hydrothermal reaction; The flash heat recovery section is used to recover the flash heat after the hydrothermal reaction, and reuse the flash heat for the hydrothermal reaction of the material in the hydrothermal reaction section; and / or, the gas outlet of the hydrothermal reaction section is connected to the preheating fluidized section, and the gas flowing out of the hydrothermal reaction section heats the material in the preheating fluidized section; and / or, the flash heat is recycled and transported to the condensation heat exchange section; A condensation heat exchange section, wherein the gas inlet is connected to the gas outlet of the preheating fluidization section, and a condensing medium flows through the condensing heat exchange section. The condensing medium is heated by the gas from the preheating fluidization section and then flows into the steam heating section; the gas from the preheating fluidization section is cooled and condensed by the condensing medium to form a low-temperature flash condensate; A flash tank connected to the material outlet of the hydrothermal reaction part and the condensation heat exchange part, and used for mixing the material from the hydrothermal reaction part and the low-temperature flash condensate to form a flash destabilized mixed material; The centrifugal separation part is connected to the flash tank to centrifugally separate the flash destabilized mixed material from the flash tank.

2. The oily sludge hydrothermal treatment energy efficient utilization system according to claim 1, characterized in that: The condensing heat exchange part includes a condensing heat exchanger and a chiller. The condensing heat exchanger is provided with a first heat exchange channel and a second heat exchange channel. The gas outlet of the preheating fluidizing part is connected to the inlet of the first heat exchange channel, and the outlet of the first heat exchange channel is connected to the flash tank. The chiller is connected to the inlet of the second heat exchange channel to supply condensing medium, and the outlet of the second heat exchange channel is connected to the steam heating part.

3. The energy efficient utilization system for hydrothermal treatment of oily sludge according to claim 2, characterized in that: The hydrothermal reaction section includes at least three reactors, the gas inlet of one reactor is connected to the gas outlet of the steam heating section to form a heating reactor, and another adjacent reactor is connected to the heating reactor to form a heating reactor. Flash steam from the heating reactor is transported to the heating reactor to heat and equalize the pressure of the material inside it, and each reactor is alternately heated and equalized in pressure in turn; the remaining gas after flash evaporation of the reactor flows to the preheating fluidized section through the gas outlet of the hydrothermal reaction section.

4. The oily sludge hydrothermal treatment energy efficient utilization system according to claim 3, characterized in that: Valves are arranged between adjacent reaction kettles.

5. The energy efficient utilization system for hydrothermal treatment of oily sludge according to claim 3, characterized in that: The preheating fluidizing section includes a raw material storage tank and a fluidizing tank, the material outlet of the raw material storage tank is connected to the material inlet of the fluidizing tank, and the material outlet of the fluidizing tank is connected to the material inlet of the hydrothermal reaction section; the flash steam heat recovery section includes a first flash steam branch and a second flash steam branch, the first flash steam branch is connected to the gas outlet of the hydrothermal reaction section and the gas inlet of the fluidizing tank, and the second flash steam branch is connected to the gas outlet of the fluidizing tank and the gas inlet of the raw material storage tank.

6. The oily sludge hydrothermal treatment energy efficient utilization system according to claim 5, characterized in that: A first coil is arranged in the fluidizing tank, the inlet of the first coil constitutes the gas inlet of the fluidizing tank, and the outlet of the first coil constitutes the gas outlet of the fluidizing tank.

7. The energy efficient utilization system for hydrothermal treatment of oily sludge according to claim 5, characterized in that: A second coil is arranged on the outer wall of the raw material storage tank, the inlet of the second coil constitutes the gas inlet of the raw material storage tank, and the outlet of the second coil constitutes the gas outlet of the raw material storage tank.

8. An operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to any one of claims 1 to 7, characterized in that: include: The preheating fluidizing section supplies materials to the hydrothermal reaction section, and the steam heating section supplies high-temperature steam to the hydrothermal reaction section. The materials in the hydrothermal reaction section undergo hydrothermal reaction, and flash evaporation occurs after the reaction. The materials after the reaction are transported to the flash tank. The remaining gas after the flash evaporation is heated by the flash heat recovery section to heat the materials in the preheating fluidizing section. The gas flowing out of the preheating fluidizing section enters the condensation heat exchange section, exchanges heat with the condensing medium to cool and condense to form a low-temperature flash condensate. The condensing medium is heated and flows into the steam heating section; the low-temperature flash condensate flows into the flash tank, and is mixed with the materials after the reaction to form a flash destabilized mixture; the flash destabilized mixture flows into the centrifugal separation section, and the flash destabilized mixture is centrifugally separated into an oil phase material, a water phase material and a solid phase material.

9. The operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to claim 8, characterized in that: The hydrothermal reaction section includes multiple reactors, and the steam heating section supplies high-temperature steam of 230-300°C to a reactor in the hydrothermal reaction section. The material in the reactor is heated and hydrothermally reacted, and flash vaporizes after the reaction. The flash steam from one reactor heats the material in another reactor and equalizes the pressure. The multiple reactors exchange heat alternately in sequence to raise the temperature of the material from 90-95°C to 140-155°C, completing the first-level waste heat utilization.

10. The operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to claim 9, characterized in that: The remaining gas after the reactor flashes is used to heat the material in the fluidized tank of the preheating fluidized section, raising the temperature of the material from 40-50°C to 70-90°C, completing the secondary waste heat utilization.

11. The operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to claim 10, characterized in that: After heating the fluidized tank, the tail gas flows to the raw material storage tank of the preheating fluidized part, raising the temperature of the original material to 40-50°C, completing the three-stage waste heat utilization.

12. The operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to claim 11, characterized in that: After heating the tank material, the tail gas enters the condensation heat exchange section, exchanges heat with the condensing medium to cool down and condense to form low-temperature flash condensate. The condensing medium is heated and flows into the steam heating section, completing the fourth-level waste heat utilization.

13. The operating method of the oily sludge hydrothermal treatment energy efficient utilization system according to claim 12, characterized in that: The low-temperature flash condensate is mixed with the reacted material in the flash tank, the material temperature is reduced to ≤80°C, and the low-temperature flash condensate and the reacted material in the flash tank are oil-oil extracted.

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