Heat recovery device for oil conversion furnace

Abstract

The utility model relates to a kind of device of matching recovery hydrogen production process associated heat of oil refining enterprise, disclose a kind of oil conversion furnace matching heat recovery device, including oil conversion furnace (1) and membrane wall waste heat boiler (3), membrane wall waste heat boiler (3) including for converging steam steam drum (30) and for dust collecting dust collecting groove (31), dust collecting groove (31) has unloading ash port (5), the conversion gas outlet of the oil conversion furnace (1) is connected with the conversion gas import of membrane wall waste heat boiler (3) by steam jacket pipe section (2), the steam of the steam drum (30) is introduced steam jacket pipe section (2) and conversion gas heat exchange by steam connection pipe (4), the conversion gas outlet of the membrane wall waste heat boiler (3) is sequentially connected with cyclone (6) and filtering device. The utility model can make fly ash in oil conversion gas with dry ash form mining, and recycle a large amount of heat in conversion gas, with good economic and environmental benefits.

Description

Technical Field

[0001] This utility model relates to a device for recovering heat generated during the hydrogen production process in oil refining enterprises. Background Technology

[0002] The conventional sources of syngas hydrogen for oil refineries are coal-to-gas and dry gas-to-hydrogen. In recent years, vacuum residue, catalytic slurry, and wax oil have been converted into oil-based conversion gas, which is then used to produce hydrogen. The conversion process using these oil products as feedstocks takes place in an oil-based conversion furnace. Because the feedstocks themselves contain a certain amount of metal salts and other solid particles, as well as carbon black generated during the combustion of carbonaceous organic matter, the oil-based conversion gas contains a large amount of fly ash dust. The current post-treatment process for the oil-based conversion gas uses a quench water washing process, which washes away the solid particles in the gas phase into the liquid phase while simultaneously cooling the gas. The ash-containing wastewater is then treated with slag water.

[0003] The aforementioned rapid cooling method not only wastes a large amount of thermal energy but also generates a large amount of ash water discharge. The ash water treatment equipment requires a huge investment and occupies a huge area, especially since the ash water area exceeds the area occupied by the oil conversion process unit. Furthermore, the hydrogen chloride and hydrogen sulfide produced in the oil conversion furnace enter the aqueous phase, forming an acidic solution that easily causes severe corrosion to the equipment. Therefore, improvements are necessary.

[0004] CN209084732U discloses a vertical water-cooled wall waste heat boiler, which has a furnace body including a membrane wall, an upper water header and a bottom header respectively disposed on the upper and lower sides of the membrane wall, and wall tubes arranged inside the membrane wall. A process gas inlet pipe and a process gas outlet pipe are disposed at the bottom of the furnace body, communicating with the inner cavity of the furnace body and arranged opposite each other. A partition wall is provided in the inner cavity, dividing the inner cavity into an adjacent first chamber and a second chamber. The process gas inlet pipe connects to the first chamber, and the process gas outlet pipe connects to the second chamber. A flow hole is provided on the partition wall, connecting the two chambers. During operation of this waste heat boiler, soft water flows in the wall tubes, and process gas flows sequentially through the process inlet pipe, the first chamber, the flow hole, and the second chamber before being discharged from the process outlet pipe. Since the process gas flows outside the wall tubes, dust adheres to the inner side of the membrane wall, avoiding the problem of easy pipe blockage caused by process gas flowing inside the tubes in traditional processes.

[0005] CN202511294U discloses a low-calorific-value, low-load waste incineration waste heat boiler, which includes a heat exchange mechanism comprising a first-stage evaporator, a high-temperature superheater, a medium-temperature superheater, a low-temperature superheater, a second-stage evaporator, and three sets of economizers. At least one ash hopper is connected to the lower end of the flue below the heat exchange mechanism, and baffles are installed in the flue above each ash hopper, between adjacent ash hoppers. This heat exchange mechanism can be used to separate high-temperature gas from fly ash when a large amount of fly ash is present.

[0006] CN118816568A discloses an integrated gas-solid sensible heat recovery device and method for by-product superheated steam. By coupling the main process gas heat recovery process with the fluidized cooling subprocess of ash particles, the gas-solid sensible heat recovery is integrated into the design, reducing the ash discharge temperature and achieving dry ash discharge. The operating temperature is 300-1300℃. The above process and device are applicable to the thermal conversion and utilization technology of carbon-containing raw materials such as coal, biomass, and waste. However, they cannot be directly used for the heat recovery of the aforementioned oil-to-gas conversion, because the metal salts contained in the oil-to-gas conversion are very likely to cause corrosion of the heat exchange tubes. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a device for recovering heat from oil-to-gas using a membrane wall waste heat boiler, that is, a heat recovery device for oil-to-gas conversion, so as to avoid the large amount of ash water generated by quenching oil-to-gas and extend the service life of the membrane wall waste heat boiler.

[0008] The technical solution adopted by this utility model to solve its technical problem is: an oil converter with a heat recovery device, including an oil converter and a membrane wall waste heat boiler. The membrane wall waste heat boiler includes a steam drum for collecting steam and an ash collection trough for ash discharge. The ash collection trough has an ash discharge port. The conversion gas outlet of the oil converter is connected to the conversion gas inlet of the membrane wall waste heat boiler through a steam jacket pipe section. The steam in the steam drum is introduced into the steam jacket pipe section through a steam pipe to exchange heat with the conversion gas. A cyclone separator and a filter device are connected in sequence after the conversion gas outlet of the membrane wall waste heat boiler.

[0009] The filtration device includes two side-by-side filters and is equipped with a nitrogen backflush line.

[0010] The steam jacket pipe section includes a connecting pipe arranged between the conversion gas outlet of the oil converter and the conversion gas inlet of the membrane wall waste heat boiler. The inner wall of the connecting pipe is provided with a cast refractory and wear-resistant material layer. A sleeve is provided inside the connecting pipe. The inlet of the sleeve is provided on the outer side of the connecting pipe, and the outlet of the sleeve is provided on the inner side of the connecting pipe. The steam pipe is connected to the inlet of the sleeve.

[0011] The beneficial effects of the present utility model are as follows: a steam jacketed pipe section is first used to perform preliminary cooling on the converted gas, so that part of the salts from the conversion furnace condenses from liquid state to solid state, avoiding the deposition of liquid metal salts in the furnace chamber of the membrane wall waste heat boiler. The membrane wall waste heat boiler serves as the main cooling device, and meanwhile, the membrane wall waste heat boiler and a cyclone separator jointly separate fly ash in the converted gas: during the main cooling process, due to the increase of the cross-sectional area in the furnace chamber, the flow velocity of the oil converted gas decreases, so that the fly ash in the oil converted gas settles into the ash collecting tank of the membrane wall waste heat boiler, realizing preliminary separation of fly ash. The converted gas discharged from the membrane wall waste heat boiler enters the cyclone separator for further fly ash separation, and is thoroughly filtered and separated for fly ash in the gasification gas filter, so that the fly ash in the oil converted gas is recovered in the form of dry ash without water washing, avoiding the generation of ash water, and corrosive media will not enter the water phase to cause corrosion problems. While cooling, the heat of the high-temperature oil converted gas is used for by-product steam, so that the energy is excellently recovered, and good economic and environmental benefits are achieved. Description of Drawings

[0012] Figure 1 is a structural schematic diagram of the heat recovery device matched with the oil conversion furnace of the present utility model.

[0013] Figure 2 is Figure 1 which is a structural schematic diagram of the steam jacketed pipe section in

[0014] Markings in the figures are as follows: 1-oil conversion furnace, 2-steam jacketed pipe section, 3-membrane wall waste heat boiler, 4-steam connection pipe, 5-ash discharge outlet, 6-cyclone separator, 7-filter, 21-connecting pipe, 22-casing, 23-cast refractory and wear-resistant material layer, 30-steam drum, 31-ash collecting tank. Detailed Description of the Embodiment

[0015] The present utility model is further described below with reference to the accompanying drawings.

[0016] As shown in Figure 1 , Figure 2 , the matched heat recovery device for an oil conversion furnace of the present utility model comprises an oil conversion furnace 1 and a membrane wall waste heat boiler 3, the membrane wall waste heat boiler 3 comprises a steam drum 30 for converging steam and an ash collecting tank 31 for ash discharge, the ash collecting tank 31 is provided with an ash discharge outlet 5, which is characterized in that: the converted gas outlet of the oil conversion furnace 1 is connected to the converted gas inlet of the membrane wall waste heat boiler 3 via a steam jacketed pipe section 2, the steam from the steam drum 30 is introduced into the steam jacketed pipe section 2 through a steam connection pipe 4 to exchange heat with the converted gas, a cyclone separator 6 and a filtering device are sequentially connected behind the converted gas outlet of the membrane wall waste heat boiler 3, the filtering device comprises two parallel filters 7 and is equipped with a nitrogen back-blowing pipeline.

[0017] As shown in Figure 1 and Figure 2As shown, the steam jacket section 2 includes a connecting pipe 21 arranged between the conversion gas outlet of the oil converter 1 and the conversion gas inlet of the membrane wall waste heat boiler 3. The inner wall of the connecting pipe 21 is provided with a cast refractory and wear-resistant material layer 23. A sleeve 22 is provided inside the connecting pipe 21. The inlet of the sleeve 22 is provided on the outer side of the connecting pipe 21, and the outlet of the sleeve 22 is provided on the inner side of the connecting pipe 21. The steam pipe 4 is connected to the inlet of the sleeve 22.

[0018] In the oil converter 1, oil undergoes an oxidation conversion reaction with oxygen to produce process gases such as hydrogen, carbon monoxide, and carbon dioxide, which contain metal salts, carbon black, and other fly ash. The process gas exiting the converter is at around 1300°C. Afterward, the converted gas enters the steam jacket section 2, where steam is introduced to lower the temperature of the converted gas to around 1000°C. Some of the salts carried by the converted gas change from liquid to solid due to the cooling, causing some of the salts exiting the converter to condense from liquid to solid. This allows the liquid metal salts to solidify and deposit on the surface of the refractory and wear-resistant material layer 23 of the connecting pipe 21, preventing the liquid metal salts from condensing in the furnace of the membrane wall waste heat boiler 3.

[0019] It should be noted that when connecting the steam jacket section 2, the flow direction of the conversion gas should be opposite to the flow direction of the steam inside the jacket 22 in order to achieve a better uniform cooling effect. In addition, the pressure of the steam introduced should be greater than the outlet pressure of the conversion gas of the oil conversion furnace 1 to prevent the liquid metal salt from solidifying and depositing inside the jacket 22.

[0020] The membrane wall waste heat boiler 3 serves as the main cooling device. Simultaneously, the membrane wall waste heat boiler 3 and the cyclone separator 6 work together to separate fly ash from the converted gas. During the main cooling process, due to the increased cross-sectional area and larger internal space within the furnace, fly ash does not block the channels. The oil-to-gas flow rate decreases, allowing the fly ash to settle and enter the ash collection trough 31 of the membrane wall waste heat boiler for initial separation. The converted gas exiting the membrane wall waste heat boiler enters the cyclone separator 6 for further fly ash separation. The fly ash is then thoroughly filtered and separated in the filter 7, ensuring that the fly ash in the oil-to-gas is extracted as dry ash without water washing, avoiding the generation of ash water and preventing corrosive media from entering the aqueous phase and causing corrosion. Simultaneously with cooling, the steam drum 30 produces steam. Part of this steam enters the steam jacket section 2 through the steam connector 4 to cool the high-temperature converted gas. The surplus steam is utilized as a common heat source or raw material. The heat from the high-temperature oil-to-gas is used for by-product steam, resulting in excellent energy recovery and significant economic and environmental benefits. The fly ash entering the ash collection trough 31 is dry particulate matter, which can be periodically discharged and collected through the ash discharge port 5. The process gas exiting the membrane wall waste heat boiler 3 enters the cyclone separator 6. Under the action of the cyclone separator 6, the fly ash falls and further separates the solid particles in the process gas. Finally, the particles in the process gas are thoroughly filtered by the filter 7 containing filter media. This filter is used in parallel with one on and one on standby. That is, when one filter is full, it switches to the other. The switched-out filter is regenerated by backflushing with nitrogen.

[0021] In the steam jacket section 2, the refractory and wear-resistant material layer 23 has a good anti-corrosion effect. When the external connecting pipe metal shows signs of corrosion, the steam jacket section 2 can be replaced. Compared with the equipment, land area and other investment or maintenance of membrane wall waste heat boilers used to treat a large amount of ash water, it is labor-saving and convenient. Therefore, this utility model also has good economic and environmental benefits.

Claims

1. A heat recovery device for an oil converter, comprising an oil converter (1) and a membrane wall waste heat boiler (3), wherein the membrane wall waste heat boiler (3) comprises a steam drum (30) for collecting steam and an ash collection trough (31) for discharging ash, the ash collection trough (31) having an ash discharge port (5), characterized in that: The conversion gas outlet of the oil converter (1) is connected to the conversion gas inlet of the membrane wall waste heat boiler (3) through the steam jacket pipe section (2). The steam from the steam drum (30) is introduced into the steam jacket pipe section (2) through the steam pipe (4) to exchange heat with the conversion gas. A cyclone separator (6) and a filter device are connected in sequence after the conversion gas outlet of the membrane wall waste heat boiler (3).

2. The heat recovery device matching with the oil conversion furnace according to claim 1, characterized in that: The filtration device includes two side-by-side filters (7) and is equipped with a nitrogen backflush line.

3. A heat recovery device matched with an oil conversion furnace according to claim 1 or 2, characterized in that: The steam jacket section (2) includes a connecting pipe (21) arranged between the conversion gas outlet of the oil converter (1) and the conversion gas inlet of the membrane wall waste heat boiler (3). The inner wall of the connecting pipe (21) is provided with a cast refractory and wear-resistant material layer (23). A sleeve (22) is provided inside the connecting pipe (21). The inlet of the sleeve (22) is provided on the outside of the connecting pipe (21), and the outlet of the sleeve (22) is provided on the inside of the connecting pipe (21). The steam pipe (4) is connected to the inlet of the sleeve (22).

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