Biomass Energy Small-Scale Combined Heat and Power Systems

2017 ◽  
pp. 1-24
Author(s):  
Daniel Büchner ◽  
Andreas Ortwein ◽  
Ernst Höftberger ◽  
Volker Lenz
Keyword(s):  
Power Systems ◽  
Combined Heat And Power ◽  
Biomass Energy ◽  
Small Scale

Biomass Energy Small-Scale Combined Heat and Power Systems

2018 ◽  
pp. 629-651
Author(s):  
Daniel Büchner ◽  
Andreas Ortwein ◽  
Ernst Höftberger ◽  
Volker Lenz
Keyword(s):  
Power Systems ◽  
Combined Heat And Power ◽  
Biomass Energy ◽  
Small Scale

scholarly journals Biomass Potential from Agricultural Waste for Energetic Utilization in Greece

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1095 ◽  
Author(s):  
Spyridon Alatzas ◽  
Konstantinos Moustakas ◽  
Dimitrios Malamis ◽  
Stergios Vakalis
Keyword(s):  
Agricultural Waste ◽  
Combined Heat And Power ◽  
Biomass Energy ◽  
Small Scale ◽  
Energy Potential ◽  
Annual Basis ◽  
Mediterranean Countries ◽  
Biomass Resources ◽  
Gasification Technology

The alignment of the Greek national legislation with the corresponding EU legislation has enhanced the national efforts to pursue renewable Combined Heat and Power (CHP) projects. The scope of the present study has been the identification of the available biomass resources and the assessment of their potential. In this paper, we present the results from the administrative regions of Crete, Thessaly, and Peloponnese. The levels of lignocellulosic biomass in Greece are estimated to be 2,132,286 tonnes on an annual basis, values that are very close to the cases of other Mediterranean countries like Italy and Portugal. In respect to the total agricultural residues, Crete produces 1,959,124 tonnes/year and Thessaly produces 1,759,457 tonnes/year. The most significant streams are identified to be olive pits, olive pruning, and cotton ginning remnants, with more than 100,000 tonnes/year each. In the latter part of this manuscript, a case study is presented for the development of a CHP gasification facility in Messenia. The biomass energy potential of the area is very promising, with about 3,800,000 GJ/year. The proposed small-scale gasification technology is expected to utilize 7956 tonnes of biomass per year and to produce 6630 MWh of electricity and 8580 MWh of thermal energy.

Optimum Microturbine Sizing in Small Scale CHP Systems

2011 ◽  
Author(s):  
Mehdi Aghaei Meybodi ◽  
Masud Behnia
Keyword(s):  
Power Systems ◽  
Carbon Tax ◽  
Combined Heat And Power ◽  
Small Scale ◽  
Optimum Number ◽  
Prime Mover ◽  
Present Worth ◽  
Prime Movers ◽  
Chp System ◽  
The Impact

Microturbines are ideally suited for distributed generation applications due to their flexibility in connection methods. They can be stacked in parallel for larger loads and provide stable and reliable power generation. One of the main applications of microturbines is operating as the prime mover in a combined heat and power (CHP) system. CHP systems are considered to be one of the best ways to produce heat and power with efficient fossil fuel consumption. Further, these systems emit less pollution compared to separate productions of the same amount of electricity and heat. In order to optimally benefit from combined heat and power systems, the proper sizing of prime movers is of paramount importance. This paper presents a technical-economic method for selecting the optimum number and nominal power as well as planning the operational strategy of microturbines as the prime movers of small scale combined heat and power systems (capacities up to 500 kW) in three modes of operation: one-way connection (OWC) mode, two-way connection (TWC) mode, and heat demand following (HDF) mode. In the proposed sizing procedure both performance characteristics of the prime mover and economic parameters (i.e. capital and maintenance costs) are taken into account. As the criterion for decision making Net Present Worth (NPW) is used. In our analysis we have also considered the impact of carbon tax on the economics of generation. The proposed approach may also be used for other types of prime movers as well as other sizes of CHP system.

Assessment of Tesla Turbine Performance for Small Scale Rankine Combined Heat and Power Systems

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Van P. Carey
Keyword(s):  
Power Systems ◽  
Residential Buildings ◽  
Rankine Cycle ◽  
Combined Heat And Power ◽  
Operating Conditions ◽  
Working Fluid ◽  
Small Scale ◽  
Manufacturing Cost ◽  
Turbine Design ◽  
The Impact

For solar Rankine cycle combined heat and power systems for residential buildings and other small-scale applications (producing 1–10 kWe), a low manufacturing cost, robust, and durable expander is especially attractive. The Tesla-type turbine design has these desired features. This paper summarizes a theoretical exploration of the performance of a Tesla turbine as the expander in a small-scale Rankine cycle combined heat and power system. A one-dimensional idealized model of momentum transfer in the turbine rotor is presented, which can be used to predict the efficiency of the turbine for typical conditions in these systems. The model adopts a nondimensional formulation that identifies the dimensionless parameters that dictate performance features of the turbine. The model is shown to agree well with experimental performance data obtained in earlier tests of prototype Tesla turbine units. The model is used to explore the performance of this type of turbine for Rankine cycle applications using water as a working fluid. The model indicates that isentropic efficiencies above 0.75 can be achieved if the operating conditions are tailored in an optimal way. The scalability of the turbine design, and the impact of the theoretical model predictions on the development of solar combined heat and power systems are also discussed.

scholarly journals Long-term optimization case studies for combined heat and power system

2009 ◽  
Vol 13 (4) ◽  
pp. 49-60 ◽  
Author(s):  
Apostolis Polyzakis ◽  
Areti Malkogianni ◽  
Eli Gomes ◽  
Kostas Zapounidis
Keyword(s):  
Power Systems ◽  
Gas Turbines ◽  
Energy Demand ◽  
Combined Heat And Power ◽  
Small Scale ◽  
Market Conditions ◽  
Full Load ◽  
Power Stations ◽  
Electricity Infrastructure

In the next years distributed poly-generation systems are expected to play an increasingly important role in the electricity infrastructure and market. The successful spread of small-scale generation either connected to the distribution network or on the customer side of the meter depends on diverse issues, such as the possibilities of technical implementation, resource availability, environmental aspects, and regulation and market conditions. The aim of this approach is to develop an economic and parametric analysis of a distributed generation system based on gas turbines able to satisfy the energy demand of a typical hotel complex. Here, the economic performance of six cases combining different designs and regimes of operation is shown. The software Turbomatch, the gas turbine performance code of Cranfield University, was used to simulate the off-design performance of the engines in different ambient and load conditions. A clear distinction between cases running at full load and following the load could be observed in the results. Full load regime can give a shorter return on the investment then following the load. In spite combined heat and power systems being currently not economically attractive, this scenario may change in future due to environmental regulations and unavailability of low price fuel for large centralized power stations. Combined heat and power has a significant potential although it requires favorable legislative and fair energy market conditions to successfully increase its share in the power generation market.

Radial Inflow Turbine Assessment for Small-Scale Concentrated Solar Rankine Combined Heat and Power Technology

2010 ◽  
Author(s):  
Deborah A. Sunter ◽  
Van P. Carey ◽  
Zack Norwood
Keyword(s):  
Rural Communities ◽  
Power Systems ◽  
Residential Buildings ◽  
Combined Heat And Power ◽  
Operating Conditions ◽  
Geometric Parameters ◽  
Small Scale ◽  
Brayton Cycle ◽  
Analysis Tools ◽  
Radial Inflow Turbine

Recent studies suggest that small scale (5–10kW) distributed solar Rankine combined heat and power could be a viable renewable energy strategy for displacing fossil fuel use in residential buildings, small commercial buildings, or developing rural communities. One of the primary obstacles of scaling down solar Rankine technology to this level is finding an appropriate expander design. This paper considers the radial-inflow turbine for such an application. Although well-tested methodologies exist for design analysis of radial inflow turbines, existing analysis tools are generally focused on machines using a combustion gases in a Brayton cycle. Use of Rankine cycle working fluids under conditions optimal for small scale Rankine solar systems result in turbine operating conditions that can be dramatically different from those in combustion-based Brayton cycle power systems. This investigation explored how analysis tools developed by NASA and others for conventional Brayton cycle power systems can be adapted to analyze and design radial inflow expanders for small scale Rankine solar combined heat and power systems. Using a 1D model derived from analysis methodologies used by NASA for conventional aerospace gas turbine power applications, the effect of reduced power output on performance is explored. Since the model contains several non-dimensional variables, a variety of geometries are surveyed, and performance sensitivity to various geometric parameters is observed. The interplay between radial inflow turbine performance and cycle efficiency for the system is examined in detail. Several fluids are compared to access how critical temperature and the shape of the saturation dome affect thermodynamic performance of the cycle and efficiency of the turbine. Conclusions regarding optimal fluids and geometric parameters for the radial-inflow turbine are discussed.

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