Page 39 - ITAtube Journal 2/2019

Technical Papers
Combined-cycle installations are therefore, “currently being built in large numbers worldwide,” accord- ing to Mücher.
Combined-cycle power plant
for Malaysia
The rapidly advancing industriali- sation of this ambitious emerging economy is having an impact on electricity demand: on average, this is increasing by around four percent year-on-year. In order to keep up with the power demands of its population of 31 million, and the growing number of indus- trial facilities, Malaysia is invest- ing in the construction of new and ef cient power plants.
The Prai combined-cycle power plant is in the town of Seberang Perai in the Penang region. With a capacity of around one giga- watt and an ef ciency of over 60 percent, according to the operator it is one of the most powerful and ef cient gas- red power plants in South East Asia. It produces around seven percent of all Malay- sia’s electricity. The plant is oper- ated by Tenaga Northern (TNBP), a fully-owned subsidiary of the Tenaga Nasional Berhad electric utility company.
High-pressure valves
protect pumps
The 50 Hz H-Class power plant built by Siemens comprises two so-called power trains, each con- sisting of one state-of-the-art gas red turbine, one water-cooled generator and one steam turbine with auxiliary systems. Two units, each with three centrifugal pumps made by the Korean pump man- ufacturer Hyosung Goodspring are in use here. These pumps are protected by six high-pressure valves from Schroeder Valves. The valves can withstand the highest pressures, in order to protect the
pumps in the Malaysian power gen- eration facility from the damage that could occur if the minimum ow is not maintained, according to Schroeder Valves’ owner, Axel Mücher. The design of the auto- matic recirculation valve ensures that pumps and installations are protected from the effects of highly uctuating pump loads and extended operation under partial load conditions. “This is achieved through a special, fully automatic minimum ow control system, which ensures a matched minimum ow.”
Combined-cycle power plants gain in importance
The state-owned electric utility Electricity Generating Authority of Thailand has also ordered a com- bined-cycle power plant. This facil- ity some 40 km south of Bangkok, with a total installed output capacity of 1,200 megawatts, should start supplying around 1.5 million Thai households with electricity from 2019. Siemens is constructing this power plant in a single shaft con guration. “In this construction, the core com- ponents (the gas turbine, the generator and the steam turbine) are connected to each other via a
single drive shaft,” according to Siemens. This plant will be charac- terised by a high ef ciency, short start-up times, and by its exibil- ity in responding to rapid changes in load. Thailand is dependent on imports of lique ed petroleum gas, so modern, high-ef ciency combined-cycle power plants are gaining in importance.
Combined-cycle plants are enjoy- ing increasing popularity world- wide. Siemens has received an order from Panama for six SGT-800 gas turbines. The industrial gas turbines, together with a steam turbine as part of a combined-cy- cle power plant, will produce around 440 megawatts of elec- trical power. This will cover the electricity requirements of approx- imately 1.9 million of Panama’s residents.
Supporting renewable energy
A natural gas- red combined-cy- cle power plant with a capac- ity of 1,000 megawatts is being constructed in Lawrence Country, Pennsylvania by Kiewit Power Constructors Co. The North Amer- ican power plant is designed for rapid, exible operation, and is intended to support the integra-
ITAtube Journal No2/May 2019
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