Production system of urea

Abstract

The invention relates to a production system of urea, which comprises a stripper which is sequentially connected with a low pressure decomposition tower, a low pressure methylamine condenser and a low pressure methylamine condenser level tank in series, and is characterized by also comprising an energy recovery system which comprises a piston power exchanger with a high pressure liquid inlet, a high pressure liquid outlet, a hydraulic oil outlet and a hydraulic oil inlet, and two ports of a hydraulic motor are respectively connected with one port of the hydraulic oil outlet and a hydraulic oil tank; the other port of the hydraulic oil tank is connected with the hydraulic oil inlet, and the hydraulic motor is also connected with a fluid coupling, a high pressure methylamine pump, a clutch and a variable frequency motor in series sequentially; and the piston power exchanger is connected between the stripper and the low pressure decomposition tower in parallel, and the high pressure methylamine pump is respectively connected with the low pressure methylamine condenser level tank and a methylamine fluid high pressure scrubber. The whole system is controlled by a PLC (Programmable Logic Controller), and the high pressure energy generated in the production process can be converted into kinetic energy, so the use of electric energy is reduced, and the production cost is reduced.

Description

technical field [0001] The present invention specifically relates to a urea production system, in particular to a urea production system capable of recycling high-pressure energy generated in the production process. Background technique [0002] "Energy recovery" refers to the process of converting the energy that has been used into energy that can be used continuously through a specific device. [0003] Many production processes in the petrochemical industry have a large number of fluids with residual pressure. For these high-pressure media, a large part of them are first decompressed to the required low pressure value through a pressure reducing valve, and then the energy is released or re-entered. Process flow, or direct emptying. In the process of decompression and discharge, a large amount of residual pressure energy is converted into heat energy and lost in the environment, causing hundreds of thousands of kilowatts of potential energy to be wasted, which is a pity fo...

AI Technical Summary

Problems solved by technology

[0007] For fertilizer production, since the medium is mostly in the condition of small flow and high pressure, if the hydraulic turbine unit is also used for energy recovery, due to the low specific speed, the mechanical loss is often quite large, and the recovery efficiency is generally difficult to exceed 45%. ; Moreover, the current domestic hydraulic turbine system is dominated by several big foreign brands, the price is very high, and the recycling significance is not particularly great

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