Use of Low/Mid-Temperature Solar Heat for Thermochemical Upgrading of Energy, Part I: Application to a Novel Chemically-Recuperated Gas-Turbine Power Generation (SOLRGT) System

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Na Zhang ◽  
Noam Lior
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Co2 Emissions ◽  
Thermal Energy ◽  
Fossil Fuel ◽  
Solar Thermal ◽  
Working Fluid ◽  
Solar Thermal Energy ◽  
Solar Heat ◽  
Overall Efficiency

This paper is the first part of a study presenting the concept of indirect thermochemical upgrading of low/mid temperature solar heat, and demonstration of its integration into a high efficiency novel hybrid power generation system. The proposed system consists of an intercooled chemically recuperated gas turbine (SOLRGT) cycle, in which the solar thermal energy collected at about 220 °C is first transformed into the latent heat of vapor supplied to a reformer and then via the reforming reactions to the produced syngas chemical exergy. The produced syngas is burned to provide high temperature working fluid to a gas turbine. The solar-driven steam production helps to improve both the chemical and thermal recuperation in the system. Using well established technologies including steam reforming and low/mid temperature solar heat collection, the hybrid system exhibits promising performance: the net solar-to-electricity efficiency, based on the gross solar thermal energy incident on the collector, was predicted to be 25–30%, and up to 38% when the solar share is reduced. In comparison to a conventional CRGT system, 20% of fossil fuel saving is feasible with the solar thermal share of 22%, and the system overall efficiency reaches 51.2% to 53.6% when the solar thermal share is increased from 11 to 28.8%. The overall efficiency is about 5.6%-points higher than that of a comparable intercooled CRGT system without solar assist. Production of NOx is near zero, and the reduction of fossil fuel use results in a commensurate ∼20% reduction of CO2 emissions. Comparison of the fuel-based efficiencies of the SOLRGT and a conventional commercial Combined Cycle (CC) shows that the efficiency of SOLRGT becomes higher than that of CC when the solar thermal fraction Xsol is above ∼14%, and since the SOLRGT system thus uses up to 12% less fossil fuel than the CC (within the parameter range of this study), it commensurately reduces CO2 emissions and saves depletable fossil fuel. An economic analysis of SOLRGT shows that the generated electricity cost by the system is about 0.06 $/kWh, and the payback period about 10.7 years (including 2 years of construction). The second part of the study is a separate paper (Part II) describing an advancement of this system guided by the exergy analysis of SOLRGT.

Use of Low/Mid-Temperature Solar Heat for Thermochemical Upgrading of Energy, With Application to a Novel Chemically-Recuperated Gas-Turbine Power Generation (SOLRGT) System

2009 ◽  
Author(s):  
Na Zhang ◽  
Noam Lior
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Energy ◽  
Fossil Fuel ◽  
High Efficiency ◽  
Solar Thermal ◽  
Working Fluid ◽  
Solar Thermal Energy ◽  
Solar Heat ◽  
Overall Efficiency

This paper presents the concept of indirect thermochemical upgrading of low/mid temperature solar heat, and demonstration of its integration into a high efficiency novel hybrid power generation system. The proposed system consists of an intercooled chemically recuperated gas turbine (SOLRGT) cycle, in which the solar thermal energy collected at about 220°C is first transformed into the latent heat of vapor supplied to a reformer and then via the reforming reactions to the produced syngas chemical exergy. The produced syngas is burned to provide high temperature working fluid to a gas turbine. The solar-driven steam production helps to improve both the chemical and thermal recuperation in the system. Using well established technologies including steam reforming and low/mid temperature solar heat collection, the hybrid system exhibits promising performance: the net solar-to-electricity efficiency, based on the gross solar thermal energy incident on the collector, was predicted to be 25–30%, and it can reach up to 35% when the solar share is reduced. In comparison to conventional CRGT system, 30% of fossil fuel saving is feasible with the solar thermal share of 26%, and the system overall efficiency reaches 51.2% to 53.6% when the solar thermal share is increased from 11 to 28.8%. The overall efficiency is about 5.7%-points higher than that of a comparable intercooled CRGT system without solar assist. Due to the introduction of steam into the combustion chamber, production of NOx is near zero, and the reduction of fossil fuel use results in a commensurate 23% reduction of CO2 emissions as compared with the comparable intercooled CRGT system without solar assist.

The Potential for Integrating Solar Thermal Energy in Both Centralized and Decentralized Systems in Egypt

2018 ◽  
Author(s):  
Ramy Imam ◽  
Mohamed Yassin
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Developing Country ◽  
Thermal Energy ◽  
Solar Thermal ◽  
Energy Prices ◽  
Solar Thermal Energy ◽  
Electricity Prices ◽  
Renewable Energy Technologies ◽  
Energy Technologies

There is an increasing need for the integration of renewable energy into the energy sector in Egypt. As the electricity subsidies are residing for consumers in Egypt, electricity prices are increasing. This increase in energy prices can be mitigated by the integration of renewable energy technologies. One of the most promising renewable energy technologies that will help stabilize the energy situation in Egypt, is Solar Thermal Energy. Solar Thermal Energy has a great potential in Egypt due to the availability and intensity of direct irradiance in Egypt. Therefore, Egypt has an amazing opportunity as a developing country to start perusing solar thermal technologies; these technologies include decentralized and centralized technologies. Decentralized technologies are targeted more for regular consumers and centralized technologies are targeted more for power generation and industries.

scholarly journals Process analysis of solar steam reforming of methane for producing low-carbon hydrogen

RSC Advances ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12582-12597 ◽  
Author(s):  
Enkhbayar Shagdar ◽  
Bachirou Guene Lougou ◽  
Yong Shuai ◽  
Enkhjin Ganbold ◽  
Ogugua Paul Chinonso ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Thermal Energy ◽  
Steam Reforming ◽  
Fossil Fuel ◽  
Process Analysis ◽  
Solar Thermal ◽  
Low Carbon ◽  
Solar Thermal Energy ◽  
Steam Reforming Of Methane

Integrating solar thermal energy into conventional SRM technology is a promising approach for low-carbon hydrogen production based on fossil fuel in near and midterm.

System and component modelling of a low temperature solar thermal energy conversion cycle

2013 ◽  
Vol 24 (4) ◽  
pp. 51-62
Author(s):  
Shadreck M. Situmbeko ◽  
Freddie L. Inambao
Keyword(s):  
Low Temperature ◽  
Solar Energy ◽  
Thermal Energy ◽  
Electrical Power ◽  
Solar Thermal ◽  
Working Fluid ◽  
Small Scale ◽  
Solar Thermal Energy ◽  
Solar Field ◽  
Conversion Technology

Solar thermal energy (STE) technology refers to the conversion of solar energy to readily usable energy forms. The most important component of a STE technology is the collectors; these absorb the shorter wavelength solar energy (400-700nm) and convert it into usable, longer wavelength (about 10 times as long) heat energy. Depending on the quality (temperature and intensity) of the resulting thermal energy, further conversions to other energy forms such as electrical power may follow. Currently some high temperature STE technologies for electricity production have attained technical maturity; technologies such as parabolic dish (commercially available), parabolic trough and power tower are only hindered by unfavourable market factors including high maintenance and operating costs. Low temperature STEs have so far been restricted to water and space heating; however, owing to their lower running costs and almost maintenance free operation, although operating at lower efficiencies, may hold a key to future wider usage of solar energy. Low temperature STE conversion technology typically uses flat plate and low concentrating collectors such as parabolic troughs to harness solar energy for conversion to mechanical and/or electrical energy. These collector systems are relatively cheaper, simpler in construction and easier to operate due to the absence of complex solar tracking equipment. Low temperature STEs operate within temperatures ranges below 300oC. This research work is geared towards developing feasible low temperature STE conversion technology for electrical power generation. Preliminary small-scale concept plants have been designed at 500Wp and 10KWp. Mathematical models of the plant systems have been developed and simulated on the EES (Engineering Equation Solver) platform. Fourteen candidate working fluids and three cycle configurations have been analysed with the models. The analyses included a logic model selector through which an optimal conversion cycle configuration and working fluid mix was established. This was followed by detailed plant component modelling; the detailed component model for the solar field was completed and was based on 2-dimensional segmented thermal network, heat transfer and thermo fluid dynamics analyses. Input data such as solar insolation, ambient temperature and wind speed were obtained from the national meteorology databases. Detailed models of the other cycle components are to follow in next stage of the research. This paper presents findings of the system and solar field component.

scholarly journals Application of Solar Thermal Energy for Medium Temperature Heating in Automobile Industry

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 19
Author(s):  
Anagha Pathak ◽  
Kiran Deshpande ◽  
Sandesh Jadkar
Keyword(s):  
Solar Energy ◽  
Thermal Energy ◽  
Automobile Industry ◽  
Storage Tank ◽  
Fossil Fuel ◽  
Heating System ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Medium Temperature

There is a huge potential to deploy solar thermal energy in process heat applications in industrial sectors. Around 50 % of industrial heat demand is less than 250 °C which can be addressed through solar energy. The heat energy requirement of industries like automobile, auto ancillary, metal processing, food and beverages, textile, chemical, pharmaceuticals, paper and pulp, hospitality, and educational institutes etc. can be partially met with solar hybridization based solutions. The automobile industry is one of the large consumers of fossil fuel energy in the world. The automobile industry is major economic growth driver of India and has its 60 % fuel dependence on electricity and remaining on oil based products. With abundant area available on roof top, and need for medium temperature operation makes this sector most suitable for substitution of fossil fuel with renewable solar energy. Auto sector has requirement of heat in the temperature range of 80-140 oC or steam up to 2 bar pressure for various processes like component washing, degreasing, drying, boiler feed water preheating, LPG vaporization and cooling. This paper discusses use of solar energy through seamless integration with existing heat source for a few processes involved in automobile industries. Integration of the concentrated solar thermal technology (CST) with the existing heating system is discussed with a case study for commonly used processes in auto industry such as component washing, degreasing and phosphating. The present study is undertaken in a leading automobile plant in India. Component cleaning, degreasing and phosphating are important processes which are carried out in multiple water tanks of varying temperatures. Temperatures of tanks are maintained by electrical heaters which consumes substantial amount of electricity. Non-imaging solar collectors, also known as compound parabolic concentrators (CPC) are used for generation of hot water at required process temperature. The CPC are non-tracking collectors which concentrate diffuse and beam radiation to generate hot water at required temperature. The solar heat generation plant consists of CPC collectors, circulation pump and water storage tank with controls. The heat gained by solar collectors is transferred through the storage tank to the process. An electric heater is switched on automatically when the desired temperature cannot be reached during lower radiation level or during non-sunny hours/days. This solar heating system is designed with CPC collectors that generate process heating water as high as 90OC. It also seamlessly integrates with the existing system without compromising on its reliability, while reducing electricity consumption drastically. The system is commissioned in April, 2013 and since then it has saved ~ 1,75,000 units of electricity/year and in turn 164 MT of emission of CO2 annually.

Trends and Opportunities in Direct-Absorption Solar Thermal Collectors

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Patrick Phelan ◽  
Todd Otanicar ◽  
Robert Taylor ◽  
Himanshu Tyagi
Keyword(s):  
Energy Conversion ◽  
Thermal Energy ◽  
Solar Thermal ◽  
Working Fluid ◽  
Direct Absorption ◽  
Solar Thermal Energy ◽  
Thermal Energy Conversion ◽  
Recent Developments ◽  
Solar Thermal Collectors ◽  
Photocatalytic Reactions

Efficient conversion of sunlight into useful heat or work is of increasing global interest. Solar-to-thermal energy conversion, as opposed to solar-to-electricity, is enabled by solar thermal collectors that convert sunlight into heat at some useful temperature. We review here recent developments in solar thermal energy conversion. Our emphasis is on “direct-absorption” solar thermal collectors, in which incident sunlight is absorbed directly by a working fluid. This contrasts with conventional solar thermal collectors where the sunlight strikes and is absorbed by a solid receiver, which then transfers heat to the working fluid. Both liquid-based and gas-based direct-absorption collectors are described, although liquid-based systems are emphasized. We propose that if “direct-absorption” technologies could be developed further, it would open up a number of emerging opportunities, including applications exploiting thermochemical and photocatalytic reactions and direct absorption of a binary fluid for absorption refrigeration.

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