Solar Trough Integration Into Combined Cycle Systems

Solar Energy ◽  
2002 ◽  
Author(s):  
Ju¨rgen Dersch ◽  
Michael Geyer ◽  
Ulf Hermann ◽  
Scott A. Jones ◽  
Bruce Kelly ◽  
...  
Keyword(s):  
Power Plants ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Parabolic Trough ◽  
Successful Operation ◽  
Power Cycle ◽  
Cycle System ◽  
Cycle Systems ◽  
Combined Cycle Plant ◽  
Solar Technology

Parabolic trough solar technology has over 125 plant-years of successful operation at nine commercial Solar Electric Generating Systems (SEGS) power plants that are operating near Barstow, California. These solar plants utilize conventional steam Rankine turbine-generator systems, and as a result most people associate parabolic trough solar technology with steam Rankine cycle power plants. Although these plants are clearly optimized for their particular application, other power cycle designs may be appropriate in other situations. Of particular interest is the integration of parabolic trough solar technology with combined cycle power plant technology, a configuration called the integrated solar combined cycle system (ISCCS). Four potential projects in India, Egypt, Morocco, and Mexico are considering the ISSCS configuration. This paper compares the performance, cost, and carbon emissions of ISCCS and SEGS plants with a standard combined cycle plant.

Development of the Trilateral Flash Cycle System: Part 1: Fundamental Considerations

1993 ◽  
Vol 207 (3) ◽  
pp. 179-194 ◽  
Author(s):  
I K Smith
Keyword(s):  
Power Systems ◽  
Power Plants ◽  
Rankine Cycle ◽  
World Market ◽  
Low Grade ◽  
Heat Sources ◽  
Two Phase ◽  
Cycle System ◽  
Cycle Systems ◽  
Power Recovery

The world market for systems for power recovery from low-grade heat sources is of the order of £1 billion per annum. Many of these sources are hot liquids or gases from which conventional power systems convert less than 2.5 per cent of the available heat into useful power when the fluid is initially at a temperature of 100° C rising to 8–9 per cent at an initial temperature of 200°C. Consideration of the maximum work recoverable from such single-phase heat sources leads to the concept of an ideal trilateral cycle as the optimum means of power recovery. The trilateral flash cycle (TFC) system is one means of approaching this ideal which involves liquid heating only and two-phase expansion of vapour. Previous work related to this is reviewed and details of analytical studies are given which compare such a system with various types of simple Rankine cycle. It is shown that provided two-phase expanders can be made to attain adiabatic efficiencies of more than 75 per cent, the TFC system can produce outputs of up to 80 per cent more than simple Rankine cycle systems in the recovery of power from hot liquid streams in the 100–200°C temperature range. The estimated cost per unit net output is approximately equal to that of Rankine cycle systems. The preferred working fluids for TFC power plants are light hydrocarbons.

A Comparative Thermoeconomic Study of Hybrid Solar Gas-Turbine Power Plants

2013 ◽  
Author(s):  
James Spelling ◽  
Björn Laumert ◽  
Torsten Fransson
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
First Generation ◽  
Combined Cycle ◽  
Parabolic Trough ◽  
Electricity Cost ◽  
Trade Offs ◽  
Combined Cycle Plant ◽  
Solar Power Plants ◽  
Combined Cycles

The construction of the first generation of commercial hybrid solar gas-turbine power plants will present the designer with a large number of choices. To assist decision making, a thermoeconomic study has been performed for three different power plant configurations, namely simple- and combined-cycles as well as simple-cycle with the addition of thermal energy storage. Multi-objective optimization has been used to identify Pareto-optimal designs and highlight the trade-offs between minimizing investment costs and minimizing specific CO2 emissions. The solar hybrid combined-cycle plant provides a 60% reduction in electricity cost compared to parabolic trough power plants at annual solar shares up to 20%. The storage integrated designs can achieve much higher solar shares and provide a 7–13% reduction in electricity costs at annual solar shares up to 90%. At the same time, the water consumption of the solar gas-turbine systems is significantly lower than conventional steam-cycle based solar power plants.

Evaluation of the Effect of Firing Temperature, Cycle, Engine Configuration, Components, and Bottoming Cycle on the Overall Thermal Efficiency of an Indirectly Coal-Fired Gas Turbine Based Power Plant

2006 ◽  
Author(s):  
Richard P. Johnston
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Turbine Engine ◽  
Combined Cycle Plant ◽  
Plant Power

Potential LHV performance of an indirect coal-fired gas turbine-based combined cycle plant is explored and compared to the typical LHV 35–38 % thermal efficiencies achievable with current coal-fired Rankine Cycle power plants. Plant performance with a baseline synchronous speed, single spool 25:1 pressure ratio gas turbine with a Rankine bottoming cycle was developed. A coal-fired High Temperature Advanced Furnace (HITAF) supplying 2000° F. (1093° C.) hot pressurized air for the gas turbine was modeled for the heat source. The HITAF concept along with coal gas for supplemental heating, are two important parts of the clean coal technology program for power plants. [1,2] From this baseline power plant arrangement, different gas turbine engine configurations with two pressure ratios are evaluated. These variations include a dual spool concentric shaft gas turbine, dual spool non-concentric shaft arrangement, intercooler, liquid metal loop re-heater, free power turbine (FPT) and post HITAF duct burner (DB). A dual pressure Heat Recovery Steam Generator (HRSG) with varying steam pressures to fit conditions is used for each engine. A novel steam generating method employing flash tank technology is applied when a water-cooled intercooler is incorporated. A halogenated hydrocarbon working fluid is also evaluated for lower temperature sub-bottoming Rankine cycle equipment. Current technology industrial gas turbine component performance levels are applied to these various engines to produce a range of LHV gross gas turbine thermal efficiency estimates. These estimates range from the lower thirties to over forty percent. Overall LHV combined cycle plant gross thermal efficiencies range from nearly forty to over fifty percent. All arrangements studied would produce significant improvements in thermal efficiency compared to current coal-fired Rankine cycle power plants. Regenerative inter-cooling, free power turbines, and dual-spool non-concentric shaft gas turbine arrangements coupled with post-HITAF duct burners produced the highest gas turbine engine and plant efficiency results. These advanced engine configurations should also produce operational benefits such as easier starting and much improved part power efficiency over the baseline engine arrangement. An inter-turbine liquid metal re-heat loop reduced engine thermal efficiency but did increase plant power output and efficiency for the example studied. Use of halogenated hydrocarbons as a working fluid would add to plant power output, but at the cost of significant additional plant equipment.

Optimization Studies for Integrated Solar Combined Cycle Systems

2001 ◽  
Author(s):  
Bruce Kelly ◽  
Ulf Herrmann ◽  
Mary Jane Hale
Keyword(s):  
High Pressure ◽  
Steam Generator ◽  
Heat Recovery ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Saturated Steam ◽  
Heat Recovery Steam Generator ◽  
Parabolic Trough ◽  
Solar Plant ◽  
Combined Cycle Plant

Abstract The integrated solar plant concept was initially proposed by Luz Solar International [1] as a means of integrating a parabolic trough solar plant with modern combined cycle power plants. An integrated plant consists of a conventional combined cycle plant, a solar collector field, and a solar steam generator. During sunny periods, feedwater is withdrawn from the combined cycle plant heat recovery steam generator, and converted to saturated steam in the solar steam generator. The saturated steam is returned to the heat recovery steam generator, and the combined fossil and solar steam flows are superheated in the heat recovery steam generator. The increased steam flow rate provides an increase in the output of the Rankine cycle. During cloudy periods and at night, the integrated plant operates as a conventional combined cycle facility. Two studies on integrated plant designs using a General Electric Frame 7(FA) gas turbine and a three pressure heat recovery steam generator are currently being conducted by the authors. Preliminary results include the following items: 1) the most efficient use of solar thermal energy is the production of high pressure saturated steam for addition to the heat recovery steam generator; 2) the quantity of high pressure steam generation duty which can be transferred from the heat recovery steam generator to the solar steam generator is limited; thus, the maximum practical solar contribution is also reasonably well defined; 3) small annual solar thermal contributions to an integrated plant can be converted to electric energy at a higher efficiency than a solar-only parabolic trough plant, and can also raise the overall thermal-to-electric conversion efficiency in the Rankine cycle; and 4) annual solar contributions up to 12 percent in an integrated plant should offer economic advantages over a conventional solar-only parabolic trough power plant.

Combined-Cycle System With Novel Bottoming Cycle

1984 ◽  
Vol 106 (4) ◽  
pp. 737-742 ◽  
Author(s):  
A. I. Kalina
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Rankine Cycle ◽  
Energy System ◽  
Combined Cycle ◽  
Heat Sources ◽  
Cycle System ◽  
Energy Cycle ◽  
Cycle Systems ◽  
Energy Advantage

A new thermodynamic energy cycle has been developed using a multicomponent working agent. This cycle is designed to replace the currently used Rankine Cycle as a bottoming cycle for a combined-cycle energy system as well as for generating electricity using low-temperature heat sources. Several combined power systems based on this cycle have been designed and cost-estimated. The efficiency of this cycle is from 1.6 to 1.9 times higher than that of the Rankine Cycle system, at the same border conditions. The investment cost per unit of power output for this cycle is lower than that for the Rankine Cycle system in approximately direct proportion to the energy advantage. The application of this cycle as a bottoming cycle in combined-cycle systems involves the use of an energy system which utilizes heat from the exhaust of a gas turbine, resulting in an increase in overall efficiency of up to 20 percent above the efficiency of the combined systems using the Rankine bottoming cycle. As a result, a thermal efficiency in the range of 50–52 percent can be achieved using a conventional gas turbine. The project to build the first experimental installation is now in progress. This installation is to become operational at the end of 1984.

scholarly journals Ruhrchemie/Ruhrkohle’s Technical Version of the Texaco Coal Gasifier as Part of a Combined Cycle Plant

1982 ◽  
Author(s):  
B. Cornils ◽  
J. Hibbel ◽  
P. Ruprecht ◽  
R. Dürrfeld ◽  
J. Langhoff
Keyword(s):  
High Pressure ◽  
Power Plants ◽  
Coal Gasification ◽  
Operating Time ◽  
Combined Cycle ◽  
Gas Generation ◽  
Load Following ◽  
Gasification Process ◽  
Steady State Operation ◽  
Combined Cycle Plant

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.

scholarly journals Root Cause Analysis of Outages in Combined-Cycle Power Plants

1984 ◽  
Author(s):  
R. L. Duncan ◽  
H. W. Brown
Keyword(s):  
Control System ◽  
Data Base ◽  
Power Plants ◽  
Combined Cycle ◽  
System Failures ◽  
Root Cause ◽  
Combined Cycle Plant ◽  
Equipment Failures ◽  
Plant Equipment ◽  
Insight Into

A data base system has been developed to analyze root causes of failures and unplanned outages in combined-cycle power plants and related equipments. Raw data in the form of plant work orders and outage reports are provided by thirteen utilities. Data encompasses both scheduled and unscheduled maintenance activities involving all plant equipments of mostly combined cycle installations. Primary objectives are to evaluate combined-cycle plant maintenance records to determine root causes of equipment failures, to analyze maintenance data to identify key areas for reliability, availability, and maintainability (RAM) improvement, and to develop an automated data processing system for feedback to project participants. ERAS (EPRI Reliability Assessment System) data were analyzed to determine failure rates and mean downtimes of critical equipment used in combined-cycle plants and integrated gasification combined-cycle plants of the future. A primary ERAS data requirement is to document plant equipment failures involving planned outages, unplanned outages, and noncurtailing maintenance. Maintenance data are mailed directly from the plant on a monthly or weekly basis. In order to maintain significant coordination and feedback, documentation is also mailed by ARINC Research to manufacturers and EPRI project personnel. ERAS is foremost a repository, based on dBASE II software, of raw data records which address combined-cycle plant equipment scheduled and unscheduled maintenance activity. By using dBASE II commands, data contained in “DAILY”, “MONTHLY”, “PROBLEMS”, and “FIREHRS” data base files (DBFs) are analyzed in many ways. Data may be separated by manufacturer or utility. RAM statistics may be analyzed according to six data hierarchies, grouping data by common plant design, system, subsystem, or components. Special report forms can be developed depending on specific data processing needs. During 1982 a total of 1744 maintenance records for the thirteen participating plants were processed. Seventy percent of the events were noncurtailing, of which 612 events involved component failures. The data base included 968 failure events to over 200 different combined-cycle plant components each described by a three digit code. Component repairs accounted for over 50 percent of these failures. Detailed descriptions of these failures identifying causes and failed piece parts can be listed by the computer from the “PROBLEMS” DBF using “FRM’s SYSCOMP” (failures grouped by components) or “SYSPLANT” (failures grouped by plant). It is concluded that work orders do provide insight into possible root cause and can assist engineering in followup failure investigations, although discussions with power plant personnel are often required for additional insight into root cause. The extent of successful root cause determination in the ERAS data base is difficult to quantify due to different root cause interpretations. However, project efforts have successfully identified the failed piece part in 86 percent of equipment failures. An analysis of plant reliability problems showed that failures of combustion turbine and heat recovery boiler panel controls and remote sensing equipment are the most frequent cause of combined-cycle plant unavailability. Each plant appears to have specific problem areas generic to these control system failures. Generic problems were observed in drum level set points, control valves, panel cards and timers, computers and data links, flame scanners, and thermo-couples. Many of the control related problems documented in ERAS records identify the failed part number of the control circuit affected. It is expected that these documented control system failures will begin to yield better insight into root cause as the number of records increase, and cause and effect relationships are established.

DEVELOPMENT AND ANALYSIS OF AN INTEGRATED MILD/PARTIAL GASIFICATION COMBINED (IMPGC) CYCLE

2021 ◽  
pp. 1-34
Author(s):  
Ting Wang ◽  
Henry Long
Keyword(s):  
Power Plants ◽  
Energy Content ◽  
Energy Resource ◽  
Rankine Cycle ◽  
High Energy ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Efficient Manner ◽  
Volumetric Heating ◽  
Partial Gasification

Abstract Around 50% of the world's electrical power supply comes from the Rankine cycle, and the majority of existing Rankine cycle plants are driven by coal. Given how unattractive coal is as an energy resource in spite of its high energy content, it becomes necessary to find a way to utilize coal in a cleaner and more efficient manner. Designed as a potential retrofit option for existing Rankine cycle plants, the Integrated Mild/Partial Gasification Combined (IMPGC) Cycle is an attractive concept in cycle design that can greatly increase the efficiency of coal-based power plants, particularly for retrofitting an old Rankine cycle plant. Compared to the Integrated Gasification Combined Cycle (IGCC), IMPGC uses mild gasification to purposefully leave most of the volatile matters within the feedstock intact (hence, yielding more chemical energy) compared to full gasification and uses partial gasification to leave some of the remaining char un-gasified compared to complete gasification. The larger hydrocarbons left over from the mild gasification process grant the resulting syngas a higher volumetric heating value, leading to a more efficient overall cycle performance. This is made possible due to the invention of a warm gas cleanup process invented by Research Triangle Institute (RTI), called the High Temperature Desulfurization Process (HTDP), which was recently commercialized. The leftover char can then be burned in a conventional boiler to boost the steam output of the bottom cycle, further increasing the efficiency of the plant, capable of achieving a thermal efficiency of 47.9% (LHV). This paper will first analyze the individual concepts used to create the baseline IMPGC model, including the mild and partial gasification processes themselves, the warm gas cleanup system, and the integration of the boiler with the heat recovery steam generator (HRSG). This baseline will then be compared with four other common types of power plants, including subcritical and ultra-supercritical (USC) Rankine cycles, IGCC, and natural gas. The results show that IMPGC consistently outperforms all other forms of coal-based power. IMPGC is more efficient than the standard subcritical Rankine cycle by nine percentage points, more than a USC Rankine cycle by nearly four points, and more than IGCC by seven points.

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