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Another water-saving project in Weihua Group’s water supply and drainage workshop has passed the acceptance assessment. Author/Source: Weihua Group Date: 12-16-2020 Clicks: 69 On December 14, the renovation of the drainage system for the steam-water separator in Weihua Group’s S4 power generation system successfully passed the acceptance assessment. The S4 power generation system for position 451 makes use of the 40 t/h of low-pressure saturated steam available in excess from the Weihua S4 pipeline. By utilizing this excess heat, a power generation facility that makes use of saturated steam waste heat is established, which enables heat recovery, saves condensate water, reduces production costs, and improves corporate efficiency. The project is implemented in the EMC mode by Xi’an Shanggu Energy Saving Service Technology Co., Ltd., and consists of a 1×5MW condensing steam turbine generator set, its control system, as well as related auxiliary facilities for recovering waste heat. Since it was completed and put into operation in June 2019, it has generated 33.64 million kWh of electricity, resulting in energy savings worth 9 million yuan. However, during operation, the S4 low-pressure saturated steam coming from the heat network frequently contained a high amount of moisture, which caused the liquid level in the steam-water separator of the turbine’s main steam pipeline to rise; sometimes this level remained at full for several hours in a row. To ensure the safe operation of the turbine, it is necessary to reduce the power generation load, which in turn leads to a decrease in steam consumption; as a result, the excess steam in the heating network must be vented. Sometimes, when the turbine is operating at low load, about ten to twenty tons of steam are vented per hour; this not only results in a large waste of steam but also reduces power generation. To address this bottleneck issue that restricts power generation capacity, after discussion between the workshop and the production department, it was decided to upgrade the condensate drainage system of the steam-water separator. The condensate pipelines located at the bottom of the steam-water separator will be modified to increase the amount of condensate that can be drained, thereby allowing the liquid level in the steam-water separator to drop quickly and eliminating this bottleneck that hinders power generation. Through the joint efforts of the Mechanical Repair and Construction Department, the Water Supply and Drainage Workshop, and Shaanxi Gas Turbine Group Company, materials such as seamless steel pipes and fittings, electric valves, manual stop valves, and cables were purchased quickly and efficiently. The Repair and Construction Department worked overtime during the period when the steam turbines were shut down to carry out the upgrades and modifications; after two weeks of performance testing, the modified systems met all the expected requirements. The acceptance assessment of this upgrade project enables the S4 power generation system at site 451 to make better use of the by-product steam generated by the units in phases I and II, which also contributes to the company’s efforts in water conservation, emission reduction, as well as energy and resource savings.