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In the energy sector, waste-to-energy power generation is a vital green and environmentally friendly solution, playing a significant role in achieving carbon peaking and carbon neutrality goals. As a critical component of steam turbines, the performance of the vacuum system directly affects power generation efficiency.
On December 24, 2025, leveraging its professional expertise and extensive experience, T-ALL Inspection Group successfully completed the vacuum system leak mitigation project for Unit #1 of Shenzhen Energy Environmental Protection Eastern Plant, setting a new benchmark for the industry.
Shenzhen Energy Environmental Protection Eastern Plant is currently the world’s largest single-unit waste-to-energy power facility, with a daily municipal solid waste processing capacity of 5,000 tons, playing a crucial role in urban energy supply and environmental protection. However, in November 2025, the vacuum tightness test results of Unit #1 exceeded the acceptable limits specified in DL/T 1055-2021.
The vacuum system is often referred to as the “lungs” of a steam turbine, as its condition has a direct impact on unit operating efficiency. Once ambient air infiltrates the system, steam heat exchange efficiency declines, turbine back pressure rises, and energy consumption increases. Long-term operation under such conditions may also lead to oxidation and corrosion.
The vacuum system boundary includes exhaust systems, condensers, low-pressure cylinders, shaft seals, and drain pipelines. With numerous potential leakage paths and extremely small leak rates, conventional methods such as soap bubble testing or isolation techniques are unable to locate leaks accurately. As a result, leak mitigation must be carried out while the unit remains in continuous operation.
Drawing on strong technical capabilities and extensive project experience, T-ALL Inspection’s leak testing team adopted the helium mass spectrometry sniffing method to carry out the mitigation work. By applying tracer gas online and scanning welds, flanges, valve stems, and reserved ports point by point, the team precisely identified leakage locations.
Once leaks were identified, the team responded swiftly, applying high-temperature-resistant sealing compounds and performing flange tightening to carry out sealing repairs. After six consecutive days of operation, 12 leakage points were successfully documented, repaired, and verified as qualified through retesting. The only remaining dynamic sealing defect has been accurately located and will be addressed offline during the next planned shutdown.Throughout the entire mitigation process, unit operating parameters remained unchanged, with the load consistently maintained at rated capacity. Under the supervision of the plant owner, the post-treatment vacuum tightness test results confirmed that all indicators met the required standard limits, and the mitigation objectives were fully achieved.
Entrust “Scale” to Size, and “Precision” to Professionals
The vacuum system mitigation project for Unit #1 at Shenzhen Energy Environmental Protection Eastern Plant represents another successful application by T-ALL Inspection Group in achieving precise detection and repair of micro-leakages under continuous operation conditions for large-scale waste-to-energy units.
This project not only verified the applicability and cost-effectiveness of online helium mass spectrometry leak detection technology in this field, but also provided the industry with a replicable and scalable technical solution for vacuum system management—delivering both economic and environmental benefits.
From “unable to locate” to “effectively resolved,” T-ALL Inspection achieved maximum reliability with minimal operational intervention. The work does not stop here: the remaining dynamic sealing defect will continue to be tracked and fully sealed during the next outage window to ensure long-term stability of the vacuum system.
T-ALL Inspection Group remains committed to addressing vacuum system challenges for clients in the energy and environmental protection sectors. By providing end-to-end professional solutions covering inspection, leak localization, and repair, we help clients accurately identify vacuum leakage points, efficiently complete mitigation, and continuously ensure system reliability—supporting the creation of “worry-free vacuum” benchmark facilities and jointly building a greener, lower-carbon, safer, and more efficient industrial ecosystem.
