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Effective Results from Technical Upgrades to Improve the Quality and Efficiency of Desalinated Water in Shaanxi Chemical Industry Author/Source: Shaanxi Chemical Industry Date: 2022-12-11 Clicks: 54 On November 25, the technical upgrade project related to the turbine condensate system in Shaanxi Chemical Industry’s desalinated water system was completed. Since then, the system has been operating stably for half a month, with improvements seen in indicators such as the condensate recovery temperature, raw water temperature, and steam consumption – all of which have seen significant reductions or improvements compared to before. This has truly achieved the goal of enhancing quality and efficiency in operations. The turbine condensate heat exchanger in the desalinated water section is responsible for the recovery of condensate in the company’s chemical processing system. As winter sets in, the load on the desalinated water system increases, and the amount of condensate recovered is higher. In the second-stage desalination heat exchange system, the temperature difference between hot and cold fluids decreases, resulting in reduced heat exchange efficiency. This leads to elevated temperatures in the turbine tank, frequent alarms due to high turbine tank temperatures, and poses a threat to the safe and stable operation of the system. In response to this issue, the leadership team and technical staff of the Power Plant attached great importance to it and visited the site on multiple occasions to assess the situation. After calculating the heat exchange area of the tubular heat exchanger, it was found that the diameter of the DN100 pipes used for the refrigerant and cooling water streams was too small, resulting in a low flow rate of the refrigerant and cooling water. Coupled with the dirt that accumulated over time inside the shell side of the heat exchanger, these two factors combined to lead to poor heat exchange efficiency. The Power Plant immediately held a special meeting to discuss solutions, deciding to carry out technical upgrades in two aspects: firstly, replacing the refrigerant pipeline of the turbine condensate heat exchanger with one of DN200 size to increase the refrigerant flow rate ； On the other hand, taking advantage of this renovation opportunity, a large amount of flushing water was used to clean the inside of the heat exchanger shell side. Once the plan was finalized, the branch factory immediately submitted a request to the Mechanical and Power Department, reached out to the raw material supplier to have the relevant piping delivered, and swiftly commenced the work related to technical upgrades, with the aim of resolving this issue that was hindering the operation of the system as soon as possible. Since the refrigerant pipeline of the desalinated water turbine condensate heat exchanger is 100 meters long, it took half a month to pre-fabricate the main pipelines in the initial stage. Next was the work of modifying the diameters of the refrigerant inlet and outlet ports; first, it was necessary to cut off the existing primary refrigerant pipeline, and shortly after that the temperature in the turbine water tank rose to around 65°C. To avoid disrupting the normal operation of the system, technicians from the Power Plant and the Maintenance Department discussed the situation and decided to complete the connection between the primary refrigerant pipeline and the heat exchanger as quickly as possible. After 10 hours, by 8 p.m. on November 25th, the last welding joint was completed. Following pressure testing and leak checks, the heat exchanger was put into operation successfully, with its heat exchange efficiency significantly improved. Through this technical upgrade, the condensate recovery temperature is reduced by about 10°C, while the raw water temperature increases by around 7–8°C; as a result, 6 tons of steam are saved per hour in winter, achieving two benefits at once.