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The renovation of the ammonia evaporation cooling system in Workshop 2 of Shaanxi Coking Chemicals was completed successfully. Author/Source: Shaanxi Coking Chemicals Co., Ltd. Date: 2021-06-11. Clicks: 20. With the arrival of summer, hot weather has quietly set in. For those working in the chemical production sector, summer is a season during which it is difficult to maintain control over various production process parameters. An increase in water temperature leads to a decrease in the efficiency of the heat exchanger, as well as an increase in the temperature of the outlet fluid. In the design of the wastewater heat exchanger for the ammonium sulfate ammonia vaporization tower, the cooling medium used is circulating water. During the summer, when the water temperature reaches 27–32°C, even if the water valve feeding into the ammonia heat exchanger is opened to its maximum, the temperature of the wastewater exiting the exchanger remains above 40°C. This makes it difficult to meet the requirements regarding the temperature of the water fed into the biological treatment process, thereby severely affecting the efficiency of biological wastewater treatment. To completely resolve this issue, Workshop 2 for Chemical Production organized personnel to conduct on-site inspections, carried out thorough evaluations, and developed a reasonable renovation plan; ultimately, it was decided to change the cooling water used in the ammonia water heat exchanger to two-stage water. Without affecting production, the pipes are first laid on the pipe rack, and then connected to the pipes of the production system through butt joints to integrate them into the production system. To save time, from May 22 to 23, staff from the Workshop Equipment Management Department made use of the weekend to actively coordinate the materials required for technical upgrades. At 18:20 on the afternoon of May 23, 17 carbon steel pipes measuring 204 meters in length with a diameter of φ159, 23 DN150 elbows, DN150/125 valves, along with all the necessary flange gaskets and bolts, arrived at the site. It was officially put into effect on May 24, with workshop leaders, managers, and electricians keeping close watch and monitoring the daily progress of work. While welding pipes on the main pipe rack, the welders have to work under the scorching sunlight during the day, with the hot pipes right beside them; at night they continue their work by the light of lamps. At the work site, there are the hurried footsteps of workshop managers, the busy figures of maintenance workers, anti-corrosion teams composed of operators, painting crews... The entire area is filled with a tense and busy atmosphere. After 7 days of continuous hard work, at 12:00 a.m. on May 31, the connection between the new pipeline and the production system was successfully made, completing the entire technical renovation project for the ammonia vapor wastewater heat exchanger. As the cool chilled water flowed into the ammonia heat exchanger, everyone’s gaze turned toward the thermometer. It was observed that the temperature of the ammonia-evaporating wastewater gradually decreased, dropping to 38°C at 12:20 and further to 33°C at 12:40! Everyone shouted in unison, It worked! This is the heartfelt expression of joy from the two of them. Everyone present seemed to forget the scorching sun and the sweat flowing down their faces, with understanding smiles appearing on their brows. This renovation not only improved the heat exchange efficiency of the wastewater heat exchanger but also created the conditions for the efficient operation of the biochemical system, while ensuring normal ammonia evaporation production. To date, the system has been operating stably and smoothly, achieving the expected results