| HRSGs and boilers


stable operation from low load to baseload with excellent cyclic operation;


faster startup due to continuous flow and less water inventory, which allow rapid heating; highly flexible operation as the OT HRSG can efficiently handle varying loads and quick changes;


implementation of an integrated water chemistry concept, allowing better impurity control and eliminating the need for a 50% condensate polisher, decreasing total plant cost; and


the required steam turbine admission conditions to be consistently achieved more swiftly.


GE Vernova has booked and executed more than 20 OT HRSGs downstream of its H-class GTs for both 50 Hz and 60 Hz applications with the first plant being Track 4A in Malaysia, which entered commercial operation in January 2021. With the energy sector undergoing a transformative shift, driven by the growing need for more sustainable, flexible, and more efficient generation technologies, gas-fired power plants remain essential in ensuring grid reliability. In this evolving landscape, HRSG technology plays a critical role, particularly in combined cycle power plants that demand high efficiency and operational flexibility.


As a result, start-up times have become more aggressive over time. In the 2000s a typical hot start duration was 70 minutes with all plant components brought online in unison. In 2010s we saw a shift towards unrestricted start-up of the GT, with start-up time around 30 minutes. Today we see unrestricted GT ramp rates and start-up times of less than 20 minutes with the water steam cycle decoupled and brought online separately. The need for flexibility coupled with more elevated steam conditions – from the past 565°C/165 bar to 600°C/185 bar – due to demands for higher plant efficiencies, has


Track 4A combined cycle power plant, Malaysia. Two 1x1 9HA.02 power blocks with GE Vernova OT HRSGs. Photo: GE Vernova


introduced a need for austenitic stainless steel for some HRSG components, leading to the necessity of dissimilar metal welds (DMW) transitioning from austenitic stainless steel to 9% chromium alloys (ferritic steel). We produce these in-house developed DMWs within our own factories to meet the stringent fabrication requirements and install them at strategic locations in the HRSG. With a manufacturing facility in Changwon, South Korea, and another one in Dung Quat, Vietnam, GE Vernova’s in-house capability to manufacture pressure part modules together with a well established supply chain helps us to deliver highly reliable HRSGs with increased quality assurance while directly navigating supply constraints.


HRSGs integrated with carbon capture


GE Vernova is also executing strategies for reducing the amount of CO2


GE Vernova 1x1 9HA.02 power block integrated with post-combustion CCS plant with EGR at Net Zero Teesside Power, UK. Image: GE Vernova


Cooling tower CO2 compressor tower CO2 absorber emitted per unit of


electricity generated in a combined cycle power plant. This involves implementing measures such as enhancing plant efficiency, reducing carbon content in fuel by using lower carbon alternatives like hydrogen, and adopting carbon capture and storage/utilisation technologies. The landmark Net Zero Teesside Power project in the UK, the world’s first combined cycle power plant with integrated CCS plant under execution, exemplifies the integration of 9HA power island equipment with CCS and exhaust gas recirculation (EGR) technology, with the HRSG an integral part engineered to enable the elimination of CCS flue gas blowers. This plant, which is expected to generate over 740 MW, capture up to 2 million tons of CO2


annually and transport it via pipeline to secure offshore sequestration, demonstrates a combination of innovation, efficiency, and sustainability, helping to drive the energy transition forward.


CO2


desorption tower Amine storage tank


Controls


Direct contact cooler (carbon capture system)


HRSG Gas turbine Steam turbine


Direct contact cooler (EGR system)


www.modernpowersystems.com | October 2025 | 11


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47