Steam heat energy recycling process for carbon dioxide gas stripping method urea production

Abstract

The invention relates to a steam heat energy recycling process for carbon dioxide gas stripping method urea production. The steam heat energy recycling process comprises the following steps that S1, asteam flash tank is installed in an urea boundary zone, and high temperature condensate of a gas-liquid separator is directly sent into the steam flash tank before entering a steam condenser; and S2,a pipe is allocated to an outlet of an intermediate hot water buffer tank to reach a urea steam condensate tank, the potential difference is used for sending back the steam condensate of the steam flash tank to the steam condensate tank for water supplementing. After the process is improved, the high transfer water temperature is lowered from 130 DEG C-140 DEG C to 120 DEG C-125 DEG C, so that the absorption effect of a high-pressure scrubber is ensured, unnecessary parking is prevented, and the operation cycle is prolonged; the condensate obtained after heat exchange in a high transfer waterjacket enters a low-pressure steam saturator, a heat source is used again, and more low-pressure steam is used for external use. Meanwhile, parking maintenance is reduced, long-term operation of theequipment is ensured, after transformation is carried out, the load of a subsequent low-pressure absorption tower is reduced, the empty amount of the low-pressure absorption tower is reduced, and meanwhile, the environmental pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of recycling steam heat energy in urea production, in particular to a technology for recycling steam heat energy in urea production by carbon dioxide stripping. Background technique [0002] With the continuous expansion of the production capacity of the urea industry and the degree of market saturation, and under the pressure of environmental protection, the cost continues to rise, and higher requirements are put forward for various consumption indicators. Optimizing the process operation and saving cost and consumption are imminent. How to reduce the urea processing It is imperative to make full use of steam heat energy and reduce steam consumption. [0003] At present, in the steam recovery and utilization of the steam condensate tank, all the steam condensate generated in the process of the urea main unit is collected into the steam condensate tank, the number of steam traps is large, the operation perio...

AI Technical Summary

Problems solved by technology

Due to the poor water quality of the circulating cooling water, which contains sediment and dirt, the high-profile water heat exchanger has serious tube scaling after long-term operation, and the heat exchange effect is seriously reduced. The outlet process index of the high-profile water cooler is 120-130°C , and it often reaches 135°C during operation, which directly affects the absorption reaction in the high-pressure scrubber. The incomplete absorption reaction will cause the ammonia and carbon dioxide in the high-pressure scrubber to rise, not only resulting in increased ammonia consumption, but also a large amount of raw material venting, resulting in subsequent absorption. The effect is poor, and the large amount of venting will cause pollution to the environment

[0005] At present, in the utilization of waste boiler steam heat energy, the synthesis workshop produces 2.2MPA waste boiler saturated steam, decompresses the 2.2MPA waste boiler steam to 0.8MPA and supplies it to the alcohol workshop, and sends the low-pressure steam to the low-pressure steam pipe after decompression to 0.4MPA However, the process is relatively complicated. After the pressure of the 0.4MPA low-pressure steam pipe network is saturated or there is a problem in the refined alcohol section, the waste boiler steam cannot be fully utilized.