Application of GE Low Load Package on an Existing District Heating Power Plant: A Case Study

2020 ◽  
Author(s):  
Antonio Mambro ◽  
Francesco Congiu ◽  
Francesco Piraccini
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
District Heating ◽  
Low Pressure ◽  
Heating Power ◽  
Low Pressure Turbine ◽  
Low Load ◽  
Flow Through ◽  
Last Stage

Abstract The continuous increase of variable renewable energy and fuel cost requires steam turbine power plants to operate with high flexibility. Furthermore, the reduction in electricity price is forcing many existing and new district heating power plants to further optimize the heat production to maintain a sustainable business. This situation leads to low pressure steam turbines running at very low volume flow for an extended time. In this work, a case study of an existing 30 MWel district heating power plant located in Europe is presented. The customer request was the removal of the steam turbine last two stages along with the condenser to maximize steam delivery for district heating operations. However, based on the experience gained by GE on low load during the last years, the same heat production has been guaranteed without any significant impact on the existing unit, excluding any major modification of the plant layout such as last stage blading and condenser removal. Making use of the latest low flow modeling, the minimum cooling flow through the low-pressure turbine has been reduced by more than 90% compared to the existing unit. Optimization of the hood spray system and logic will reduce trailing edge erosion during low load operation leading to a significant extension in the last stage blade lifetime. These modifications, commercialized by GE as the Advanced Low Load Package (ALLP), provide a cheap, flexible and effective solution for the customer. With today’s knowledge, GE has the capability to guarantee low load operation minimizing the mass flow through the low-pressure turbine to the minimum required for safe operation. As a benefit to the customer, this option allows a gain in operational income of about 1.5 M€ per year.

Application of GE Low Load Package on an Existing District Heating Power Plant: A Case Study

2021 ◽  
Author(s):  
Antonio Mambro ◽  
Francesco Congiu ◽  
Francesco Piraccini
Keyword(s):  
Power Plant ◽  
District Heating ◽  
Heating Power ◽  
Low Load

Performance Considerations in Replacement of Low-Pressure Turbine Rotors for Nuclear Power Plants: A Case Study

2005 ◽  
Author(s):  
Komandur S. Sunder Raj
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Low Pressure ◽  
Turbine Rotor ◽  
Modeling Tools ◽  
Low Pressure Turbine ◽  
Turbine Rotors ◽  
The Impact

In recent years, the nuclear power industry has witnessed profound changes in terms of renewal of operating licenses and power uprates. Renewal of operating licenses for an additional 20 years beyond the original licensed period of 40 years entails several considerations relating to aging management, performance, reliability, availability, and maintainability. Power uprates range from a low of up to 2% due to improved techniques in feedwater flow measurement to a high of up to 20% for extended power uprates. Since the limitations of power uprates are generally encountered in design of the turbine cycle, the impact upon the performance, reliability, availability and maintainability of the equipment and components in the turbine cycle may vary from low or moderate to significant. Several nuclear power plant owners have already replaced the low-pressure turbine rotors of their nuclear units with improved designs to mitigate blade failures and forced outages due to stress corrosion cracking, to reduce inspection intervals and maintenance, achieve higher output due to improved efficiency, etc. Others are either embarking upon or planning similar initiatives to confront aging, performance, availability, reliability and maintainability concerns stemming from renewal of operating licenses as well as the need to accommodate higher pressures and flows accompanying the proposed power uprates. Typically, the original low-pressure turbine designs utilizing built-up rotors with shrunk-on disks are being replaced with monoblock rotors with fully integral disks, couplings, blading and shrouds. The last stage blading is also longer resulting in a larger annulus area. Since these replacement programs involve significant expenditures, several factors need to be considered in order to ensure that the objectives of the rotor replacement programs are met. Using a case study, this paper examines the various considerations involved in replacing the low-pressure turbine rotors for a nuclear power plant. Design, performance and test considerations that need to be addressed before and after the low-pressure turbine rotors are replaced are discussed. The use of performance modeling tools in evaluating performance gains from low-pressure turbine rotor replacements is reviewed. Finally, the paper provides recommendations for ensuring that the objectives of a low-pressure turbine rotor replacement program are met.

Last Stage Performance Considerations in Low-Pressure Turbines of Power Plants: A Case Study

2006 ◽  
Author(s):  
Komandur S. Sunder Raj
Keyword(s):  
Power Plants ◽  
Cooling System ◽  
Low Pressure ◽  
Optimum Performance ◽  
Operating Range ◽  
Circulating Water ◽  
Last Stage ◽  
Stage Performance ◽  
Lp Turbine

The last stage blades (LSB) of low-pressure (LP) turbines power plants have been historically specified and designed on the basis of optimization studies by matching the turbine to the condenser/cooling system for a specified unit rating. LSB sizes for U.S. nuclear applications currently range from 38” to 52” for unit ratings of 600 Mwe to 1200 Mwe. LP turbine arrangements usually consist of two or three double-flow sections in parallel. Last stage end loadings (last stage mass flow divided by the last stage annulus area) vary from approximately 8,000 lb/hr-sq.ft to 14,000 lb/hr-sq.ft, with corresponding unit loadings (electrical output in megawatts divided by last stage annulus area) of 1.1 Mwe/sq.ft to 2.1 Mwe/sq.ft. Several power plants have been upgrading/replacing their LP turbines. Considerations include efficiency, reliability, power uprates, operating license renewals (nuclear), aging, inspection and, maintenance. In some cases, LP turbine rotors are being replaced with new rotors, blading and steam path. Others are replacing LP turbines with new and advanced designs incorporating improved technology, better materials, optimized steam paths, more efficient blading, longer LSB sizes, redesigned exhaust hoods, etc. Unlike the other stages in the LP turbine, the last stage performance is affected by both the upstream (load) and downstream (condenser) conditions. While the LP turbines are being upgraded or replaced, no major modifications or upgrades are being made to the condensers. To address vibration effects due to increased flows and velocities from power uprates, the condenser tubes may be staked. Circulating water pumps may or may not be upgraded depending upon the particular application. Consequently, while improvements in LP turbines lead to more efficient utilization of the available energy and higher output, the last stage performance may be out of synch with the existing condenser/cooling system. Undersized or oversized LSB sizes in relation to the unit rating and end loading may result in less than optimum performance depending upon the design and operating range of the condenser/cooling system. This paper examines the various factors that affect last stage performance of LP turbines. Using a case study, it discusses the relationships between the last stage, the unit rating, the end loading and, the operating range of the condenser/cooling system. It examines different last stage exhaust loss curves and provides recommendations for selection of LSB sizes for optimum performance.

scholarly journals Wellhead Power Plants Improvement by Introduction of Double Flashing Cycle

2019 ◽  
pp. 24-32
Author(s):  
Thomas Mutero ◽  
Peter Muchiri ◽  
Nicholas Mariita
Keyword(s):  
Power Plant ◽  
Geothermal Energy ◽  
Power Plants ◽  
Low Pressure ◽  
Geothermal Field ◽  
Power Cycle ◽  
Single Flash ◽  
Geothermal Power ◽  
Installed Capacity

Kenya Electricity Generating Company Ltd (KenGen) has harnessed geothermal energy for over thirty seven years at the Olkaria geothermal field. The total installed capacity of geothermal energy in Kenya currently stands at 703.5 MW generated mostly by single flash and binary geothermal power plants. In the 1990s KenGen considered the Wellheads concept in which modular containerized single flash power plants were to be designed, customized and built on a wellpad for optimized well potential; this approach has largely been successful currently having an installed capacity of 83.5 MW and accounting for 15.7% of KenGen's total geothermal installed capacity. This was done to address an inherent deficiency in the construction of conventional geothermal power plants which was identified as the long period taken to put up the power plants. The wells that have been drilled by KenGen and GDC, tested and shut in awaiting the installation of power plants are rated at about 600 MW. The Wellhead power plant cycle is a single flash geothermal power plant; this research intended to improve the current Wellheads power cycle by introducing a second low pressure separator to harness more energy from the wellheads, design a turbine to be driven by the low pressure steam and evaluate an economic justification for introducing the double flashing cycle. A case study was carried out at Wellhead 914 and Wellhead 915. Data collected indicated that the combined mass flow rate of brine from wells in the two wellpads was 240.4 tonne per hour. This brine was saturated at 13.5 bar-a and at a temperature of 193.40C as it exits the high pressure separator for disposal. The optimal pressure of the low pressure separation was designed at 2.5 bar-a, 127.40C and had an ability to generate 3871 kW of electric power. A turbine operating at a steam inlet pressure of 2.5 bar-a, a speed of 6804 rpm and having an exhaust pressure of 0.075 bar-a was designed. The designed turbine had 4 stages of both stationary and moving blades with a maximum rotor disc diameter of 0.62 meters and an output of 4195 kW. The simple payback period for this project was estimated to be 1.9 years with a rate of return on investment of 42.24%. This would also minimize energy wastage by improving efficiency and footprints on the environment arising from the Wellhead power plants.

Last Stage Performance Considerations in Low-Pressure Turbines of Power Plants: A Case Study

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Komandur S. Sunder Raj
Keyword(s):  
Power Plants ◽  
Cooling System ◽  
Low Pressure ◽  
Optimum Performance ◽  
Operating Range ◽  
Circulating Water ◽  
Last Stage ◽  
Stage Performance ◽  
Lp Turbine

The last stage blades (LSBs) of low-pressure (LP) turbine power plants have been historically specified and designed on the basis of optimization studies by matching the turbine to the condenser/cooling system for a specified unit rating. LSB sizes for U.S. nuclear applications currently range from 38 in. to 52 in. for unit ratings of 600 MWe to 1200 MWe. LP turbine arrangements usually consist of two or three double-flow sections in parallel. Last stage end loadings (last stage mass flow divided by the last stage annulus area) vary from approximately 8000lb∕hsqftto14,000lb∕hsqft, with corresponding unit loadings (electrical output in megawatts divided by last stage annulus area) of 1.1 MWe∕sqftto2.1MWe∕sqft. Several power plants have been upgrading/replacing their LP turbines. Considerations include efficiency, reliability, power uprates, operating license renewals (nuclear), aging, inspection, and maintenance. In some cases, LP turbine rotors are being replaced with new rotors, blading, and steam path. Others are replacing LP turbines with new and advanced designs incorporating improved technology, better materials, optimized steam paths, more efficient blading, longer LSB sizes, redesigned exhaust hoods, etc. Unlike the other stages in the LP turbine, the last stage performance is affected by both the upstream (load) and downstream (condenser) conditions. While the LP turbines are being upgraded or replaced, no major modifications or upgrades are being made to the condensers. To address vibration effects due to increased flows and velocities from power uprates, the condenser tubes may be staked. Circulating water pumps may or may not be upgraded depending upon the particular application. Consequently, while improvements in LP turbines lead to more efficient utilization of the available energy and higher output, the last stage performance may be out of synchronization with the existing condenser/cooling system. Undersized or oversized LSB sizes in relation to the unit rating and end loading may result in less than optimum performance depending upon the design and operating range of the condenser/cooling system. This paper examines the various factors that affect last stage performance of LP turbines. Using a case study, it discusses the relationships between the last stage, the unit rating, the end loading, and the operating range of the condenser/cooling system. It examines different last stage exhaust loss curves and provides recommendations for selection of LSB sizes for optimum performance.

Cracks on the Roots of Turbine Blades of the Low-Pressure Turbine in a Steam Power Plant

2015 ◽  
Vol 52 (4) ◽  
pp. 214-225 ◽  
Author(s):  
E. Plesiutschnig ◽  
R. Vallant ◽  
G. Stöfan ◽  
C. Sommitsch ◽  
M. Mayr ◽  
...  
Keyword(s):  
Power Plant ◽  
Turbine Blades ◽  
Low Pressure ◽  
Steam Power ◽  
Steam Power Plant ◽  
Low Pressure Turbine

Automating attendance recording of contingent labours at a large construction site

2012 ◽  
Vol 2 (8) ◽  
pp. 1-9
Author(s):  
Saroj Koul
Keyword(s):  
Power Plant ◽  
Radio Frequency Identification ◽  
Power Plants ◽  
Subject Area ◽  
Management Control ◽  
Class Discussion ◽  
Construction Site ◽  
Large Power ◽  
Content Type

Subject area Operations and human resourcing. Study level/applicability This case study is intended for use in graduate, executive level management and doctoral programs. The case study illustrates a combined IT and HR driven participative management control system in a flexible organization structure. It is intended for a class discussion rather than to illustrate either effective or ineffective handling of an administrative situation. Case overview The case describes the situation of managing unskilled workforces (≥14,000 workers) during the construction phase of the 4 × 250MW power plants both for purposes of turnout as well as due compensation, in the event of an accident. The approved labour forces appointed for 45 × 8 h. Man-days after a rigorous fitness test and approvals of the safety officer are allocated housing and other necessary amenities and a commensurate compensation system. Expected learning outcomes These include: illustrating typical organizational responsibility structure at a construction site of a large power plant; illustrating the planning and administrative control mechanism in implementing strategy at a construction site of a large power plant; offering students the opportunity to understand and view a typical operational (project) structure; allowing students to speculate adaptations in the wake of an ever-changing business and company environment; and providing an opportunity to introduce a power scenario in India, Indian labour laws and radio frequency identification technology and to relate this to the case in context. Supplementary materials Teaching notes are available; please consult your librarian for access.

Energy Storage Using Low-Pressure Feedwater

1985 ◽  
Vol 107 (3) ◽  
pp. 569-573 ◽  
Author(s):  
C. M. Harman ◽  
S. Loesch
Keyword(s):  
Energy Storage ◽  
Power Plants ◽  
Storage System ◽  
Energy Storage System ◽  
Low Pressure ◽  
Steam Power ◽  
Low Pressure Turbine ◽  
Availability Analysis ◽  
Steam Power Plants ◽  
And Storage

A method for increasing the peak output of steam power plants through use of a low-pressure feedwater storage system is presented. The generalized availability analysis involves only the low-pressure turbine, low-pressure feedwater heaters, and the storage system. With daily cycling and storage charging at near base load conditions, the turnaround efficiency of the energy storage system was found to approach 100 percent. Storage system turnaround efficiency is decreased when the energy is stored during plant part-load operation.

Case Study 1.2: Turning of Low Pressure Turbine Casing

2017 ◽  
pp. 25-38
Author(s):  
Oscar Gonzalo ◽  
Jose Mari Seara ◽  
Eneko Olabarrieta ◽  
Mikel Esparta ◽  
Iker Zamakona ◽  
...  
Keyword(s):  
Low Pressure ◽  
Low Pressure Turbine ◽  
Turbine Casing
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