Specified Maintenance of Steam Turbines in Geothermal Power Plants

Abstract

In a geothermal power plant the working fluid used to produce electricity is often wet steam composed of corrosives chemicals. In this situation, more frequent maintenance of the equipment is required. By constructing an overview for maintenance in geothermal power plants and how it can be done with minimum power outages and cost, the geothermal energy can be made more competitive in comparison to other energy resources. This work is constructed as a part of a project, which has the aim of mapping the maintenance management system at the Hellisheiði geothermal power plant in Iceland. The object of the project is to establish Reliability Centered Maintenance (RCM) program for Hellisheiði power plant that can be utilized to establish efficient maintenance management procedures. The focus of this paper is to examine the steam turbines, which have been defined as one of the main subsystems of the power plant at Hellisheiði. A close look will be taken at the maintenance needed for the steam turbines by studying for example which parts break down and how frequently they fail. The local ability of the staff to repair or construct turbine parts on-site is explored. The paper explores how the maintenance and condition monitoring is carried out today and what can be improved in order to reduce cost. The data collected is analyzed using Failure Mode and Effect Analysis (FMEA) in order to get an overview of the system and to help organizing maintenance and condition monitoring of the power plant in the future. Furthermore, the paper presents an overview of currently employed maintenance methods at Hellisheiði power plant, the domestic ability for maintaining and repairing steam turbines and the power plant’s need for repairs. The results show that the need for maintenance of the geothermal steam turbines at Hellisheiði power plant is high and that on-site maintenance and repairs can decrease the cost.

The Development of A Reliability Evaluation Application for Power Plant Steam Turbine Vibrations to Predict Its Failure

“…Reliability evaluation is carried out using qualitative and quantitative analysis. Failure Mode and Effect Analysis (FMEA) is frequently used to describe the potential failures and the critical components of steam turbine using qualitative assessment [3] [4][5]. A study once examined the diaphragm was the top priority of steam turbine components that should be maintained refered to the highest risk priority number (RPN) [4].…”

“…RPN was calculated by multiplying the value of Severity (S), Occurrence (O), and Detection (D). In this study, the potential failures were adapted from previous researches [3][4] and combined with direct identification. FMEA questionnaires was spreaded to 5 respondents in the power plant.…”

Perancangan Poros Turbin 5 Mw untuk Pembangkit Listrik Tenaga Panas Bumi

“…Sedangkan, Gambar 8(b) adalah siklus daya operasi sampai overhaul, di mana overhaul pada umumnya dilakukan 4 tahun sekali. Alasannya, keausan akibat erosi partikel padat yang melewati poros berpotensi menimbulkan kerusakan yang lebih besar pada poros, terutama bagian labyrinth seal setelah melewati jangka waktu tersebut [12]. Garis merah pada gambar grafik menandakan panjangnya 1 siklus pada Gambar 8(b).…”

Mechanically Alloyed CoCrFeNiMo0.85 High-Entropy Alloy for Corrosion Resistance Coatings

“…Almar Gunnarsson et al [ 15 ] reported the corrosion–erosion and wear effect on the turbine blades operating in a geothermal environment. Cost reduction in maintenance is required in order to increase the competitiveness of this type of resource in the renewable energy market.…”