In the Snam process, the medium-pressure level is too low

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1. During a ball tank transfer operation in the ammonia synthesis plant, the pressure in the medium-pressure system of the urea production unit dropped to 1.3 MPa in a very short time； 2. After the ammonia storage tank was checked and found to be in good condition, the medium-pressure level remained low and did not increase ； 3. Currently, the return water from the ammonia cooler is set at around 25%, the pressure is controlled at around 1.45 MPa, and the temperature of liquid ammonia is around 32°C ； 4. The production system is currently stable, and output consumption has not been significantly affected by changes in the pressure of the medium-pressure system. Projects that have been checked: 1. Internal leaks in equipment such as the medium-pressure quench tank E111, the medium-pressure condenser E106, and the liquid ammonia condenser E109; analysis of the circulating water ruled this out ； 2. The pressure of liquid ammonia is low and its purity is low; both are within normal ranges ； 3. The circulating water has high pressure and low temperature, with no significant changes prior to the pressure fluctuations ； 4. High-pressure pressure PI9204: 15.6 MPa; temperature at the bottom of the synthesis tower TI9202: 172°C; temperature at the outlet of the synthesis tower TI9203: 188.8°C. Operation is normal. 5. The opening degree of PI9207A is low; compared to previous productions, it has decreased by 5-6% ； 6. Internal leakage in the medium-pressure system CD (P105, P103, V105, L102); internal leakage in the safety valves; leakage of seal water at P105. On-site inspections showed normal conditions ； 7. There is no significant change in the water addition amount for the medium-pressure scrubber ； 8. The instrument display is normal. Differences in system responses: 1. The ammonia temperature at the P107 inlet decreased to 38℃ ； 2. The frequency of overheating on the fourth tray of the medium-pressure absorption tower has increased ； 3. The temperature at the top of the medium-pressure absorption tower decreases by 3-4℃ ； 4. The temperature of the medium-pressure decomposition tower, T301, is about 1°C higher (it may also be due to recent fluctuations in steam pressure) ； The system is running smoothly at present. Seeking a solution?