Precise load testing for a hydrogen-LNG hybrid gas turbine

Our client, Hanwha Corporation, announced that they have started demonstration work to increase the hydrogen mixing rate from 1% to 63% on the world’s first medium-to-largesized (78MW or more) LNG (liquefied natural gas) gas turbine generator. This hybrid generator would reduce the carbon footprint level by 23% and ensure nitrogen oxides levels fall below the standard of 50-80ppm in Korea.

Turbines are meticulously designed and have extremely fine operational parameters. The customer needed to validate the performance of their GTG by stressing turbines before and after installation to reveal potential issues. It is expected that they will be tested to their full capacity – can they handle maximum load, do they synchronize when multiple units run in parallel, and can they take and shed load without issue? During the test, the load provided has also to remain consistent and available. If not, the test would need to be restarted – delaying commissioning and increasing the fuel cost.

In order to use the local grid to support their load testing, the customer would have to get approval from Korea Electrical Construction Association (KECA) and ensure their safety standards were strictly adhered by. It was also challenging as a high power load was required, and the local grid had to support other industries as well. The customer could not take up too huge of a power load from the local grid or risk disrupting the power supply of the grid’s other customers. It would also not make financial sense to specially purchase load banks just to test their gas turbine. 

Aggreko provided a comprehensive turn key 78 MW load bank package including LV and HV cables. The hybrid turbine required thorough testing at various step loads. At each load- step, the transient response and effect on voltage and frequency needed to be measured and recorded to ensure compliance with the manufacturer’s specification.

With the help of our skilled design engineers, we were able to control the load profile precisely according to the customer’s request. During the test, various scenarios were simulated - making use of load step-ups and downs and changes in power factor. This ensured testing was thorough enough and provided the customer the assurance that the turbines could run at full capacity once they were commissioned.

Working from a central control system, we could pre-plan and program the load steps before to the test, which can reduce operator interface and risk while also guaranteeing a consistent and repeatable test.

By eliminating the customer’s need for grid power, we helped our customer avoid the need to apply for government’s approval which would be a tedious process. Our 78 MW load bank test facility also enabled our customer avoid capital expenditure as purchasing load banks for short-term testing would be unnecessary.

With the Aggreko team on-site during the project overseeing our comprehensive turn key package, the customer is now able to test its hybrid gas turbine independently through various step loads without any delays.