Externally Fired Micro-Gas Turbine and Organic Rankine Cycle Bottoming Cycle: Optimal Biomass/Natural Gas Combined Heat and Power Generation Configuration for Residential Energy Demand

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Sergio Mario Camporeale ◽  
Patrizia Domenica Ciliberti ◽  
Bernardo Fortunato ◽  
Marco Torresi ◽  
Antonio Marco Pantaleo
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Energy Demand ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale ◽  
Residential Energy ◽  
Micro Gas Turbine ◽  
Residential Energy Demand ◽  
Heat Demand

Small-scale combined heat and power (CHP) plants present lower electric efficiency in comparison to large scale ones, and this is particularly true when biomass fuels are used. In most cases, the use of both heat and electricity to serve on-site energy demand is a key issue to achieve acceptable global energy efficiency and investment profitability. However, the heat demand follows a typical daily and seasonal pattern and is influenced by climatic conditions, in particular in the case of residential and tertiary end users. During low heat demand periods, a lot of heat produced by the CHP plant is discharged. In order to increase the electric conversion efficiency of small-scale micro-gas turbine for heat and power cogeneration, a bottoming organic Rankine cycle (ORC) system can be coupled to the cycle, however, this option reduces the temperature and the amount of cogenerated heat available to the thermal load. In this perspective, the paper presents the results of a thermo-economic analysis of small-scale CHP plants composed of a micro-gas turbine (MGT) and a bottoming ORC, serving a typical residential energy demand. For the topping cycle, three different configurations are examined: (1) a simple recuperative micro-gas turbine fueled by natural gas (NG); (2) a dual fuel externally fired gas turbine (EFGT) cycle, fueled by biomass and natural gas (50% share of energy input) (DF); and (3) an externally fired gas turbine (EFGT) with direct combustion of biomass (B). The bottoming ORC is a simple saturated cycle with regeneration and no superheating. The ORC cycle and the fluid selection are optimized on the basis of the available exhaust gas temperature at the turbine exit. The research assesses the influence of the thermal energy demand typology (residential demand with cold, mild, and hot climate conditions) and CHP plant operational strategies (baseload versus heat-driven versus electricity-driven operation mode) on the global energy efficiency and profitability of the following three configurations: (A) MGT with cogeneration; (B) MGT+ ORC without cogeneration; and (C) MGT+ORC with cogeneration. In all cases, a back-up boiler is assumed to match the heat demand of the load (fed by natural gas or biomass). The research explores the profitability of bottoming ORC in view of the following trade-offs: (i) lower energy conversion efficiency and higher investment cost of biomass input with respect to natural gas; (ii) higher efficiency but higher costs and reduced heat available for cogeneration with the bottoming ORC; and (iii) higher primary energy savings and revenues from feed-in tariff available for biomass electricity fed into the grid.

Externally Fired Micro Gas Turbine and ORC Bottoming Cycle: Optimal Biomass/Natural Gas CHP Configuration for Residential Energy Demand

2015 ◽  
Author(s):  
Sergio Mario Camporeale ◽  
Patrizia Domenica Ciliberti ◽  
Bernardo Fortunato ◽  
Marco Torresi ◽  
Antonio Marco Pantaleo
Keyword(s):  
Energy Efficiency ◽  
Natural Gas ◽  
Gas Turbine ◽  
Energy Demand ◽  
Rankine Cycle ◽  
Small Scale ◽  
Residential Energy ◽  
Micro Gas Turbine ◽  
Residential Energy Demand ◽  
Heat Demand

Small scale Combined Heat and Power (CHP) plants present lower electric efficiency in comparison to large scale ones, and this is particularly true when biomass fuels are used. In most cases, the use of both heat and electricity to serve on site energy demand is a key issue to achieve acceptable global energy efficiency and investment profitability. However, the heat demand follows a typical daily and seasonal pattern and is influenced by climatic conditions, in particular in the case of residential and tertiary end users. During low heat demand periods, a lot of heat produced by the CHP plant is discharged. In order to increase the electric conversion efficiency of small scale micro turbine for heat and power cogeneration, a bottoming ORC system can be coupled to the cycle, however this option reduces the temperature and quantity of cogenerated heat available to the load. In this perspective, the paper presents the results of a thermo-economic analysis of small scale CHP plants composed by a micro gas turbine (MGT) and a bottoming Organic Rankine Cycle (ORC), serving a typical residential energy demand. For the topping cycle three different configurations are examined: 1) a simple recuperative micro gas turbine fuelled by natural gas (NG), 2) a dual fuel EFGT cycle, fuelled by biomass and natural gas (50% energy input) (DF) and 3) an externally fired gas turbine (EFGT) with direct combustion of biomass (B). The bottoming cycle is a simple saturated Rankine cycle with regeneration and no superheating. The ORC cycle and the fluid selection are optimized on the basis of the available exhaust gas temperature at the turbine exit. The research assesses the influence of the thermal energy demand typology (residential demand with cold, mild and hot climate conditions) and CHP plant operational strategies (baseload vs heat driven vs electricity driven operation mode) on the global energy efficiency and profitability of the following three configurations: A) MGT with cogeneration; B) MGT+ ORC without cogeneration; C) MGT+ORC with cogeneration. In all cases, a back-up boiler is assumed to match the heat demand of the load (fed by natural gas or biomass). The research explores the profitability of bottoming ORC in view of the following tradeoffs: (i) lower energy conversion efficiency and higher investment cost of high biomass input rate with respect to natural gas; (ii) higher efficiency but higher costs and reduced heat available for cogeneration in the bottoming ORC; (ii) higher primary energy savings and revenues from feed-in tariff available for biomass electricity fed into the grid.

Environmental Impact on the Life Cycle for Turbine Based Biomass CHP Plants

2018 ◽  
Author(s):  
Pietro Bartocci ◽  
Gianni Bidini ◽  
Paolo Laranci ◽  
Mauro Zampilli ◽  
Michele D'Amico ◽  
...  
Keyword(s):  
Life Cycle ◽  
Gas Turbine ◽  
Combustion Engine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Biomass Combustion ◽  
Small Scale ◽  
Environmental Benefit ◽  
Treatment Unit ◽  
Whole Life Cycle

Biomass CHP plants represent a viable option to produce distributed energy in a sustainable way when the overall environmental benefit is appraised on the whole life cycle. CHP plants for bioenergy conversion may consist of a gasification (IGC – Integrated Gasification Cycle) or pyrolysis (IPRP – Integrated Pyrolysis Regenerated Plant) pre-treatment unit, producing a syngas that feeds an internal combustion engine or a gas turbine. The external combustion mode is also an option, where exhaust gases from biomass combustion provide heat to either a traditional steam cycle, an ORC (Organic Rankine Cycle) or an EFGT (Externally Fired Gas Turbine). This paper focuses specifically on turbines based technologies and provides a LCA comparison of 4 main technologies suitable for the small scale, namely: EFMGT, ORC, IGC and IPRP. The comparison is carried out considering 3 different biomasses, namely a Short Rotation Forestry, an agricultural residue and an agro industrial residue at 2 different scales: micro scale (100 kw) and small scale (1 MW), being higher scales barely sustainable on the life cycle. From data derived from the Literature or experimental campaign (tests at the IPRP and gasification facilities at the University Perugia), LCA analysis were carried out and the different scenarios were compared based on two impact categories: global warming and human health. Input and output of the derived LCI are referred to the functional unit of 1 kWh electric for upstream, core and downstream processes. Results show the contribution of main processes and are discussed comparing scale, technology and feedstock.

Research on the Combined Cycle of a Biogas Micro Gas Turbine and an Organic Rankine Cycle

2019 ◽  
Vol 13 (5) ◽  
pp. 683-689
Author(s):  
Zheng Jian ◽  
Feng Zheng-Jiang ◽  
Wang Jian ◽  
Wang Yan ◽  
Li Xin-Yi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Micro Gas Turbine

Bottoming organic Rankine cycle for a small scale gas turbine: A comparison of different solutions

2013 ◽  
Vol 106 ◽  
pp. 355-364 ◽  
Author(s):  
Stefano Clemente ◽  
Diego Micheli ◽  
Mauro Reini ◽  
Rodolfo Taccani
Keyword(s):  
Gas Turbine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Small Scale

Micro Combined Plant With Gas Turbine and Organic Cycle

2008 ◽  
Author(s):  
Flavio Caresana ◽  
Gabriele Comodi ◽  
Leonardo Pelagalli ◽  
Sandro Vagni
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Turbine Unit ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Gas Turbine Unit ◽  
Principal Characteristics ◽  
Micro Gas Turbine ◽  
System A

In this paper we discuss the usefulness of a bottoming cycle applied to a micro size gas turbine unit to enhance its electric performance. A commercial 100 kWe micro gas turbine is used as a topping system; a basic thermodynamic analysis is performed to define the principal characteristics of viable vapour bottoming cycles. The analysis points to a solution adopting an Organic Rankine Cycle (ORC) with R245fa as working fluid, due both to environmental constrains and to technical criteria.

scholarly journals Environmental Impacts of a Solar Dish Coupled With a Micro-Gas Turbine for Power Generation

2021 ◽  
Vol 9 ◽  
Author(s):  
A. Agostini ◽  
C. Carbone ◽  
M. Lanchi ◽  
A. Miliozzi ◽  
M. Misceo ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Environmental Impacts ◽  
Energy Demand ◽  
Solar Power ◽  
Ghg Emissions ◽  
Primary Energy ◽  
Small Scale ◽  
Energy Mix ◽  
Micro Gas Turbine ◽  
Primary Energy Demand

Concentrated solar power (CSP) systems are regarded as a renewable energy source technology that can contribute to decoupling the energy mix from fossil fuel combustion and related environmental impacts. However, current small-scale CSP technologies (e.g., Dish-Stirling) have not entered the market yet due to high costs, complexity, and poor reliability. The EU-funded OMSoP (Optimised Microturbine Solar Power) project aimed at solving the small-scale CSP shortcomings by coupling a solar dish with the consolidated and relatively cheap technology of the micro gas turbine (MGT). In this study, an environmental life cycle assessment analysis of the production and operation of a CSP-MGT system is performed following an eco-design approach, thus identifying the environmental hotspots and how the system can be improved in terms of environmental impacts. The results of the analysis, per unit of electricity produced, were compared to other renewable technologies with the same level of dispatchability to better evaluate strengths and weaknesses of the system under exam. With regard to climate change, the greenhouse gas (GHG) emissions of the CSP-MGT system resulted in the same range as those generated by photovoltaic systems. However, the system can substantially be optimized and the GHG emissions per kWh can be reduced up to 73% with respect to the built prototype. The GHG emissions are much lower than the current Italian energy mix (by up to 94%). To reduce the environmental burden of CSP-MGT plants, the system design here considered should be revised by improving the component’s performance and significantly reducing the reflective surface and therefore the structural materials for the dish foundation and frame. The replacement of steel in the dish frame with aluminum increases all the environmental impact parameters and primary energy demand (17%–27% depending on the environmental category considered) but slightly reduces abiotic element depletion (by 9%).

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