Coal-oil slurry heating furnace system using thermal circulation liquid stream in process of hydrogenating direct liquefaction of coal

Abstract

Provided is a coal-oil slurry heating furnace system using a thermal circulation liquid stream in the process of hydrogenating direct liquefaction of coal. The thermal circulation liquid material obtained from an outlet material of the coal-oil slurry heating furnace or a downstream front reactor of coal liquefaction is returned to the inlet of the heating furnace through a circulation pump, and optimization of a flow pattern, increase of the temperature of the liquid material in the furnace and shortening of the heating time can be achieved by flexibly regulating the flow rate of the liquid material in a heating furnace tube, so that improvement of the heat transfer efficiency, slow-down of coking in the furnace tube, slow-down of corrosion of the furnace tube and increase of the flexiblerange of flow operation of the coal-oil slurry feed are facilitated, decrease of the temperature shock amplitude of an inlet pipeline of the heating furnace is facilitated when the coal slurry is interrupted, and expanding of the range of coal types for a coal hydrogenating direct liquefaction device is facilitated.

Description

technical field [0001] The invention relates to an oil-coal slurry heating furnace system in the coal hydrogenation direct liquefaction process using thermal circulation liquid flow. The thermal circulation liquid material obtained from the outlet material of the oil-coal slurry heating furnace or the downstream coal liquefaction front reactor is returned and heated by a circulating pump Furnace inlet, to flexibly adjust the flow rate of the liquid material in the heating furnace tube to achieve the optimal flow pattern, increase the temperature of the liquid material entering the furnace, and shorten the heating time, which is conducive to improving heat transfer efficiency, slowing down coking in the furnace tube, slowing down the abrasion of the furnace tube, and increasing oil and coal The operating elastic range of the slurry feed flow is beneficial to reduce the temperature shock range of the inlet pipe of the heating furnace when the coal slurry is interrupted, and is be...

AI Technical Summary

Problems solved by technology

[0014] ①The heating temperature difference of the heating furnace is large

[0016] ②The operating load of the oil-coal slurry flow in the heating furnace tube varies greatly

[0041] However, the continuous operation of the device for more than 5,000 hours indicates that it needs to be shut down twice a year for coke cleaning; although the coke cleaning technology has been gradually improved, the cleaning time of primary heating furnace coking has been shortened from more than 30 days to 7 days, but the shutdown caused by coke, The overall time for cleaning coke and resuming production is still as high as 15 to 20 days, and there are potential safety hazards, resulting in a large amount of waste of materials, energy, and manpower, which seriously shortens the normal production cycle of the device. The amount of safety hazards, environmental hazards, resource waste, and economic losses is It is astonishing and unbearable. Therefore, it is necessary to propose an economical scheme that fundamentally improves the flow state of the oil-coal slurry material and effectively inhibits the coking reaction on the wall of the furnace tube, so as to ensure the long-term safe operation of the oil-coal slurry heating furnace and improve the safety of the device. sex, economy

[0042] As mentioned above, the measures to prevent coking and optimize the flow in the pipe can relieve coking to a certain extent, but it is impossible to fundamentally solve the problem of coking, because the oil-coal slurry heating furnace of the coal hydrogenation direct liquefaction unit, its Conventional design schemes have the following technical problems that are conducive to inducing coking but not conducive to inhibiting coking:

[0043] ① The flow rate of oil-coal slurry, under the premise of maintaining the ideal flow pattern of the medium in the furnace tube, the adjustment flexibility is small. Since the inner diameter of the furnace tube cannot adopt any value and can only choose certain standard specifications, the flow rate of the medium in the furnace tube , the flow pattern is difficult to achieve optimization;

[0046] ③ When the temperature of the oil-coal slurry rises from 169°C to 300°C, the temperature of the liquid material is low, the hydrogen supply ability of the hydrogen donor agent is poor, and the ability to inhibit coking is poor;

[0047] ④The temperature of oil-coal slurry rises from 169°C to 366°C, the temperature difference is too large, and the heating time is too long, resulting in too long thermal condensation time;

[0048] ⑤ After the emergency shutdown of the coal slurry pump, the processing state of the device fluctuated drastically, and the emergency response to the accident was difficult; the process of resuming the supply of oil and coal slurry for the second time was difficult to operate

[0067] Similar technical scheme of the present invention has no report

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