Addressing the Energy Trilemma With LPG-Fuelled, Water-Free Combined Cycle Power Plants

2020 ◽  
Author(s):  
Michael Welch
Keyword(s):  
Environmental Impact ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Gas Production ◽  
Combined Cycle ◽  
Liquefied Petroleum Gas ◽  
Distributed Power ◽  
The Impact

Abstract Many parts of the world are facing the triple challenge of providing secure energy to fuel economic growth at an affordable cost while minimizing the impact of energy production on the environment. Island nations especially struggle to address this trilemma, as renewable resources are usually limited and fossil fuels imported. Traditionally such distributed power plants have relied on liquid fuels and multiple open cycle reciprocating engines to provide both redundancy and the ability to load follow across a broad load range to maximize efficiency. This approach has created high electricity prices and significant negative environmental impact, especially that attributed to CO2, NOx, and SOx. With increasing natural gas production, the availability of Liquefied Petroleum Gas (LPG) has grown, and costs have fallen, allowing the potential to switch from fuel oils to LPG to reduce environmental impacts. Energy costs and environmental impact can be further reduced by using high efficiency Gas Turbine Combined Cycle plants with dry low emissions combustion technology. However, a further hurdle facing many locations is lack of the fresh water required for combined cycle operations. LPG-fuelled Gas Turbine Combined Cycle using Organic Rankine Cycle (ORC) technology can address all aspects of this energy trilemma. This paper reviews the conceptual design of a proposed 100MW distributed power plant for an island location, based on multiple LPG-fuelled gas turbines to follow load demand, with an ORC bottoming cycle to maximize efficiency.

scholarly journals Gas Turbines - Major Greenhouse Gas Inhibitors

2015 ◽  
Vol 137 (12) ◽  
pp. 54-55
Author(s):  
Lee S. Langston
Keyword(s):  
Natural Gas ◽  
Greenhouse Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Hydrocarbon Fuel ◽  
Gas Production ◽  
Combined Cycle

This article explains how combined cycle gas turbine (CCGT) power plants can help in reducing greenhouse gas from the atmosphere. In the last 25 years, the development and deployment of CCGT power plants represent a technology breakthrough in efficient energy conversion, and in the reduction of greenhouse gas production. Existing gas turbine CCGT technology can provide a reliable, on-demand electrical power at a reasonable cost along with a minimum of greenhouse gas production. Natural gas, composed mostly of methane, is a hydrocarbon fuel used by CCGT power plants. Methane has the highest heating value per unit mass of any of the hydrocarbon fuels. It is the most environmentally benign of fuels, with impurities such as sulfur removed before it enters the pipeline. If a significant portion of coal-fired Rankine cycle plants are replaced by the latest natural gas-fired CCGT power plants, anthropogenic carbon dioxide released into the earth’s atmosphere would be greatly reduced.

scholarly journals Whisper and Roar

2014 ◽  
Vol 136 (07) ◽  
pp. 38-43
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Thermal Power ◽  
Electrical Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Marine Applications ◽  
Almost All

This article focuses on the use of gas turbines for electrical power, mechanical drive, and marine applications. Marine gas turbines are used to generate electrical power for propulsion and shipboard use. Combined-cycle electric power plants, made possible by the gas turbine, continue to grow in size and unmatched thermal efficiency. These plants combine the use of the gas turbine Brayton cycle with that of the steam turbine Rankine cycle. As future combined cycle plants are introduced, we can expect higher efficiencies to be reached. Since almost all recent and new U.S. electrical power plants are powered by natural gas-burning, high-efficiency gas turbines, one has solid evidence of their contribution to the greenhouse gas reduction. If coal-fired thermal power plants, with a fuel-to-electricity efficiency of around 33%, are swapped out for combined-cycle power plants with efficiencies on the order of 60%, it will lead to a 70% reduction in carbon emissions per unit of electricity produced.

Development and Implementation of Repair Processes for Refurbishment of W501F, Row 1 Turbine Blades

2001 ◽  
Author(s):  
Richard Curtis ◽  
Warren Miglietti ◽  
Michael Pelle
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Cycle Basis ◽  
Repair Procedure ◽  
Crack Repair ◽  
Maintenance Requirements

In recent years, orders for new land-based gas turbines have skyrocketed, as the planning, construction and commissioning of new power plants based on combined-cycle technology advances at an unprecedented pace. It is estimated that 65–70% of these new equipment orders is for high-efficiency, advanced “F”, “G” or “H” class machines. The W501F/FC/FD gas turbine, an “F” class machine currently rated at 186.5 MW (simple cycle basis), has entered service in significant numbers. It is therefore of prime interest to owners/operators of this gas turbine to have sound component refurbishment capabilities available to support maintenance requirements. Processes to refurbish the Row 1 turbine blade, arguably the highest “frequency of replacement” component in the combustion and hot sections of the turbine, were recently developed. Procedures developed include removal of brazed tip plates, coating removal, rejuvenation heat treatment, full tip replacement utilizing electron beam (EB) and automated micro-plasma transferred arc (PTA), joining methods, proprietary platform crack repair and re-coating. This paper describes repair procedure development and implementation for each stage of the process, and documents the metallurgical and mechanical characteristics of the repaired regions of the component.

Water-Free Combined Cycle Power Plants for Distributed Power Generation

2018 ◽  
Author(s):  
Michael Welch
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Air Cooling ◽  
Exhaust Gas ◽  
Plant Design ◽  
Distributed Power ◽  
Full Load

Combined Cycle Gas Turbine (CCGT) power plant offer operators both environmental and economic benefits. The high efficiency achievable across a wide load range reduces both fuel costs and CO2 emissions to atmosphere. However, the scale of the power generation plays a major role in determining both cost and efficiency: a modern large centralized CCGT of 600MW output or more will have a full load efficiency in excess of 60% and a very competitive installed cost on a US$/kW basis. The smaller gas turbines required for distributed power applications are not optimized for combined cycle operation, with potential full load efficiencies of a combined cycle scheme ranging from a little over 40% to the high 50s depending on the power output of the gas turbine, the exhaust gas conditions and the plant configuration, while the installed cost is around twice that of a large centralized CCGT on a US$/kW basis. The drawback of a conventional combined cycle plant design is the need for water, which is a scarce commodity in some regions. Air cooling of the CCGT plant can be used to reduce water consumption, but make-up water will still be required for the steam system to compensate for steam losses, blowdown etc. While the lower exhaust gas temperatures of the smaller gas turbines impact the combined cycle efficiencies achievable, they do allow Organic Rankine Cycle (ORC) technology to be considered for an alternative combined cycle configuration. This paper compares both the capital and operating costs and performance of combined cycle power plants for distributed power applications in the 30MW to 250MW power range based on conventional steam and various different ORC configurations.

scholarly journals Nigerian power sector: Why gas turbines will be relevant for the next 50 years

2020 ◽  
Vol 5 (1) ◽  
pp. 066-075
Author(s):  
Ebigenibo Genuine Saturday ◽  
Celestine Ebieto Ebieto
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Power Production ◽  
Gas Production ◽  
Combined Cycle ◽  
Photovoltaic System ◽  
Power Sector ◽  
Levelized Cost Of Electricity

Several cases of the need for continuous utilization of gas turbines for power production and why gas turbines will be relevant in the next 50 years in the Nigerian power sector are presented in this paper. Using 7 criteria; the cost of installation, operation and maintenance costs, levelized cost of electricity, capacity factor, the efficiency of energy conversion, power to size ratio/area coverage and environmental pollution, gas turbine operation was compared with wind and solar energy technologies. Gas turbine for power production appears to be more favourable in 5 out of the 7 criteria including lower installation cost which is a very important factor for poor and developing nations like Nigeria. The quantity of fuel for producing different quantities of power using gas turbines was estimated. Nigeria has huge proven reserves of natural gas which is the fuel for gas turbines. If we go for combined cycle power plants which have low specific fuel consumption (SFC), 50% of the natural gas reserves are enough to produce some 35 GW of electricity for over 50 years. The current rate of natural gas production can produce 27.06 GW of electricity at 0.06kg/s.MW sfc. It was also observed that the current installed power from gas turbines is too low compared to the power demand; hence, further installations are required. Pollution should not be an issue in installing more gas turbine plants because the gas turbine is a clean-burning engine and the present installed capacity is insignificant compared to what is obtainable in some advanced nations. The results in this work will guide gas turbine operators in planning for further installation of gas turbine power plants. The study does not rule out the need to exploit solar photovoltaic system and wind turbines in areas with high sunshine and high wind speeds respectively, for off-grid power production.

Limiting the Maintenance Impact of Frequency Regulation Duty on Simple and Combined Cycle Gas Turbine Power Plants

1997 ◽  
Author(s):  
William I. Rowen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Combined Cycle ◽  
Frequency Regulation ◽  
Cycle Fatigue ◽  
Thermally Induced ◽  
System Frequency ◽  
The Impact

As more new power plants based on gas turbines enter service, the need for these plants to participate in grid frequency regulation, as opposed to providing blocks of base load power on a dispatchable basis, increases dramatically, exposing this equipment to the potential for accelerated thermal fatigue duty. This paper proposes a methodology for quantifying and limiting the maintenance impact of rapid load changes imposed on gas turbines when required to provide frequency regulation service to the connected utility. The paper includes a discussion of the need for prime movers to participate in system frequency regulation and the impact of this type of service on gas turbine operation. The physics of thermally induced low cycle fatigue is then discussed, and the relationships are quantified using a multiple time constant approach that provides guidance for estimating the transient thermal characteristics of the turbine airfoils that are susceptible to thermally induced low cycle fatigue. This is used to develop the thermo-mechanical relationships that are pertinent to gas turbines in generator drive service. Finally, this material is related back to operational considerations in utilizing gas turbines for system frequency regulation duty.

Commercialization and Fleet Experience of the 7/9HA Gas Turbine Combined Cycle

2019 ◽  
Author(s):  
Christian Vandervort ◽  
David Leach ◽  
David Walker ◽  
Jerry Sasser
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Operating Experience ◽  
Combined Cycle ◽  
Lessons Learned ◽  
Operational Flexibility ◽  
Industrial Gas Turbine ◽  
Cycle Efficiency

Abstract The power generation industry is facing unprecedented challenges. High fuel costs and increased penetration of renewable power have resulted in greater demand for high efficiency and operational flexibility. Imperatives to reduce carbon footprint place an even higher premium on efficiency. Power producers are seeking highly efficient, reliable, and operationally flexible solutions that provide long-term profitability in a volatile environment. New generation must also be cost-effective to ensure affordability for both domestic and industrial consumers. Gas turbine combined cycle power plants meet these requirements by providing reliable, dispatchable generation with a low cost of electricity, reduced environmental impact, and broad operational flexibility. Start times for large, industrial gas turbine combined cycles are less than 30 minutes from turning gear to full load, with ramp rates from 60 to 88 MW/minute. GE introduced the 7/9HA industrial gas turbine product portfolio in 2014 in response to these demands. These air-cooled, H-class gas turbines (7/9HA) are engineered to achieve greater than 63% net combined cycle efficiency while delivering operational flexibility through deep, emission-compliant turndown and high ramp rates. The largest of these gas turbines, the 9HA.02, is designed to exceed 64% combined cycle efficiency (net, ISO) in a 1×1, single-shaft (SS) configuration. As of December 2018, a total of 32 7/9HA power plants have achieved COD (Commercial Operation Date) while accumulating over 220,000 hours of operation. These plants operate across a variety of demand profiles including base load and load following (intermediate) service. Fleet leaders for both the 7HA and 9HA have exceeded 12,000 hours of operation, with multiple units over 8,000 hours. This paper will address four topics relating to the HA platform: 1) gas turbine product technology, 2) gas turbine validation, 3) integrated power plant commissioning and operating experience, and 4) lessons learned and fleet reliability.

Short-Term Optimization of a Combined Cycle Power Plant Integrated With an Inlet Air Conditioning Unit

2020 ◽  
Author(s):  
Weimar Mantilla ◽  
José García ◽  
Rafael Guédez ◽  
Alessandro Sorce
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Air Conditioning ◽  
Combined Cycle ◽  
Plant Performance ◽  
Mixed Integer ◽  
Environmental Load ◽  
Turbine Inlet ◽  
The Impact

Abstract Under new scenarios with high shares of variable renewable electricity, combined cycle gas turbines (CCGT) are required to improve their flexibility, in terms of ramping capabilities and part-load efficiency, to help balance the power system. Simultaneously, liberalization of electricity markets and the complexity of its hourly price dynamics are affecting the CCGT profitability, leading the need for optimizing its operation. Among the different possibilities to enhance the power plant performance, an inlet air conditioning unit (ICU) offers the benefit of power augmentation and “minimum environmental load” (MEL) reduction by controlling the gas turbine inlet temperature using cold thermal energy storage and a heat pump. Consequently, an evaluation of a CCGT integrated with this inlet conditioning unit including a day-ahead optimized operation strategy was developed in this study. To establish the hourly dispatch of the power plant and the operation mode of the inlet conditioning unit to either cool down or heat up the gas turbine inlet air, a mixed-integer linear optimization (MILP) was formulated using MATLAB, aiming to maximize the operational profit of the plant within a 24-hours horizon. To assess the impact of the proposed unit operating under this dispatch strategy, historical data of electricity and natural gas prices, as well as meteorological data and CO2 emission allowances price, have been used to perform annual simulations of a reference power plant located in Turin, Italy. Furthermore, different equipment capacities and parameters have been investigated to identify trends of the power plant performance. Lastly, a sensitivity analysis on market conditions to test the control strategy response was also considered. Results indicate that the inlet conditioning unit, together with the dispatch optimization, increases the power plant’s operational profit by achieving a wider operational range, particularly important during peak and off-peak periods. For the specific case study, it is estimated that the net present value of the CCGT integrated with the ICU is 0.5% higher than the power plant without the unit. In terms of technical performance, results show that the unit reduces the minimum environmental load by approximately 1.34% and can increase the net power output by 0.17% annually.

The Effect of Alternative Turbine Cooling Schemes on the Performance of Utility Gas Turbine Powerplants

1982 ◽  
Author(s):  
Arthur Cohn ◽  
Mark Waters
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Power Plants ◽  
Heat Rate ◽  
Combined Cycle ◽  
Specific Power ◽  
Cooling Effectiveness ◽  
Turbine Cooling ◽  
The Impact ◽  
Systems Studies

It is important that the requirements and cycle penalties related to the cooling of high temperature turbines be thoroughly understood and accurately factored into cycle analyses and power plant systems studies. Various methods used for the cooling of high temperature gas turbines are considered and cooling effectiveness curves established for each. These methods include convection, film and transpiration cooling using compressor bleed and/or discharge air. In addition, the effects of chilling the compressor discharge cooling gas are considered. Performance is developed to demonstrate the impact of the turbine cooling schemes on the heat rate and specific power of Combined–Cycle power plants.

Enhancing Gas Turbine Operation With Heavy Fuel Oil

2013 ◽  
Author(s):  
Vikram Muralidharan ◽  
Matthieu Vierling
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Power Plants ◽  
High Efficiency ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Residual Oil ◽  
Heavy Fuel Oil ◽  
Hydro Power

Power generation in south Asia has witnessed a steep fall due to the shortage of natural gas supplies for power plants and poor water storage in reservoirs for low hydro power generation. Due to the current economic scenario, there is worldwide pressure to secure and make more gas and oil available to support global power needs. With constrained fuel sources and increasing environmental focus, the quest for higher efficiency would be imminent. Natural gas combined cycle plants operate at a very high efficiency, increasing the demand for gas. At the same time, countries may continue to look for alternate fuels such as coal and liquid fuels, including crude and residual oil, to increase energy stability and security. In over the past few decades, the technology for refining crude oil has gone through a significant transformation. With the advanced refining process, there are additional lighter distillates produced from crude that could significantly change the quality of residual oil used for producing heavy fuel. Using poor quality residual fuel in a gas turbine to generate power could have many challenges with regards to availability and efficiency of a gas turbine. The fuel needs to be treated prior to combustion and needs a frequent turbine cleaning to recover the lost performance due to fouling. This paper will discuss GE’s recently developed gas turbine features, including automatic water wash, smart cooldown and model based control (MBC) firing temperature control. These features could significantly increase availability and improve the average performance of heavy fuel oil (HFO). The duration of the gas turbine offline water wash sequence and the rate of output degradation due to fouling can be considerably reduced.

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