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Weihua Group’s Synthesis Workshop Takes Proactive Measures to Reduce Costs and Improve Efficiency Author/Source: Weihua Group Date: 2022-06-07 Clicks: 10 In 2021, Weihua Group’s Synthesis Workshop implemented improvements to the ammonia cooling system for unit E1901-3, enabling the ammonia synthesis plant to operate at full capacity during the summer for the first time. This year, the workshop continued to delve deeper into optimization; taking advantage of the major maintenance period, it focused on improving efficiency in order to further extract more cooling capacity from the system. After the maintenance, when the circulating water temperature was 26°C, the load of the ammonia synthesis plant increased by about 2% compared to before, reaching 105% (the same load as at the previous water temperature of 22°C), thereby increasing the plant’s operational load in summer and helping the company reduce costs and improve efficiency. Strict control is exercised over the quality of cleaning and leak repair for the water cooler E1804. Leakage at the corner welds of the tube sheet in E1804 leads to scaling on the tube sheet, which in turn blocks the pipes and reduces the heat exchange efficiency. To effectively improve the heat exchange efficiency of E1804, during this major maintenance campaign, the workshop took action in two areas: first, it ensured strict control over the quality of cleaning by assigning dedicated personnel to supervise the process throughout, to guarantee that every pipe was thoroughly cleaned ； Secondly, emphasis is placed on ensuring the quality of leak repair; based on past experience, leak repair plans are discussed in advance with Dalian Songhai, and dedicated personnel are assigned to oversee the process. Through repeated inspections, repairs, and joint verification, all leaks have been essentially eliminated. After the maintenance and restart, when the circulating water temperature was also 26°C, the temperature of the process gas at the outlet of E1804 was 5°C lower than before the maintenance, indicating a significant improvement in heat exchange efficiency. Modification of the level gauge and optimal level control for ammonia cooler E1807: Ammonia cooling is the main source of cooling capacity in the ammonia synthesis section. When the evaporation pressure of the ammonia cooler remains constant, the liquid level directly affects the efficiency of ammonia cooling. If the liquid level is too high, liquid can be carried along, causing the ammonia compressor to shut down; if the liquid level is too low, the heat exchange efficiency is reduced. There is an optimal liquid level range for the ammonia cooler to achieve maximum efficiency. Before maintenance, this level gauge exhibited large fluctuations in liquid level and frequent false readings due to clogged pressure transfer tubes. Taking the opportunity of maintenance, the pressure guiding tube of the level gauge was modified to eliminate issues such as false level readings and large fluctuations ； Through repeated experiments, the liquid level was adjusted to the optimal range; under the same conditions at the ammonia cooling inlet temperature, the temperature of the process gas after ammonia cooling decreased by about 2°C, resulting in a significant improvement in heat exchange efficiency. Eliminating faults in the anti-surge valves of the ammonia compressor: Before carrying out maintenance, a thorough inspection of the compressor revealed minor issues with the anti-surge valves in its first and second stages. Adhering to the principle that \"saving every penny translates into increased profits,\" the synthesis workshop took advantage of this major maintenance opportunity to fix these valve problems, thereby improving the operational efficiency of the ammonia compressor. This laid a solid foundation for the plant to overcome the challenges associated with peak summer operating loads, as well as to save water and electricity by reducing the number of fans used in the cooling towers during winter.