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The energy transition towards a scenario with 100% renewable energy sources (RES) for the energy system is starting to unfold its effects and is increasingly accepted. In such a scenario, a predominant role will be played by large photovoltaic and wind power plants. At the same time, the electrification of energy consumption is expected to develop further, with the ever-increasing diffusion of electric transport, heat pumps, and power-to-gas technologies. The not completely predictable nature of the RES is their well-known drawback, and it will require the use of energy storage technologies, in particular large-scale power-to-chemical conversion and chemical-to-power re-conversion, in view of the energy transition. Nonetheless, there is a lack in the literature regarding an analysis of the potential role of small–medium CCHP technologies in such a scenario. Therefore, the aim of this paper is to address what could be the role of the Combined Heat and Power (CHP) and/or Combined Cooling Heat and Power (CCHP) technologies fed by waste heat within the mentioned scenario. First, in this paper, a review of small–medium scale CHP technologies is performed, which may be fed by low temperature waste heat sources. Then, a review of the 100% RE scenario studied by researchers from the Lappeenranta University of Technology (through the so-called “LUT model”) is conducted to identify potential low temperature waste heat sources that could feed small–medium CHP technologies. Second, some possible interactions between those mentioned waste heat sources and the reviewed CHP technologies are presented through the crossing data collected from both sides. The results demonstrate that the most suitable waste heat sources for the selected CHP technologies are those related to gas turbines (heat recovery steam generator), steam turbines, and internal combustion engines. A preliminary economic analysis was also performed, which showed that the potential annual savings per unit of installed kW of the considered CHP technologies could reach EUR 255.00 and EUR 207.00 when related to power and heat production, respectively. Finally, the perspectives about the carbon footprint of the CHP/CCHP integration within the 100% renewable energy scenario were discussed.
Ronelly De Souza; Melchiorre Casisi; Diego Micheli; Mauro Reini. A Review of Small–Medium Combined Heat and Power (CHP) Technologies and Their Role within the 100% Renewable Energy Systems Scenario. Energies 2021, 14, 5338 .
AMA StyleRonelly De Souza, Melchiorre Casisi, Diego Micheli, Mauro Reini. A Review of Small–Medium Combined Heat and Power (CHP) Technologies and Their Role within the 100% Renewable Energy Systems Scenario. Energies. 2021; 14 (17):5338.
Chicago/Turabian StyleRonelly De Souza; Melchiorre Casisi; Diego Micheli; Mauro Reini. 2021. "A Review of Small–Medium Combined Heat and Power (CHP) Technologies and Their Role within the 100% Renewable Energy Systems Scenario." Energies 14, no. 17: 5338.
The aim of the paper is to identify the consequence of the Constructal Principle in the field of Thermoeconomics of (energy) production systems. This Principle has been recently formulated as an extension of the Maximum Entropy Production Principle and it has been used in literature to explain the shape and structure of all kind of flowing systems. First, the concept of Thermoeconomic Environment is defined consistently with the consumption of environmental resources and residual emissions, which inherently characterize every kind of production system. This approach allows to infer that the evolution of any energy system is strictly related to the exploitation of resources from the Thermoeconomic Environment. Moreover, the widely accepted assumption that energy systems have to be optimized by minimizing the specific resource (exergy) cost of products, has to be regarded as a consequence of a physical principle that tells us which energy systems can persist in time (to survive) and which others would be selected for extinction. The paper shows how the creation of a recycle may allow a reduction of the unit exergy cost of the product, obtaining a more sustainable behavior of the macro-system, made up by the production process together with its supply chains, consistently with the Constructal Principle. Finally, the definition of the Thermoeconomic Environment allows (at least in principle) to properly identify the resource (exergy) cost of disposing off residues and sub-products directly in the environment, without any kind of additional operation. As a consequence, residues and sub-products have to be generally converted into some kind of product by different (new) production processes, supporting the paradigm of the Circular Economy and highlighting the importance of recycling not only for system efficiency, but for system surviving. More generally, the results obtained may be regarded as the physical justifications of the evolutionary tendency toward the more and more complex and highly circular pathways that can be observed in both natural and artificial (energy) production systems.
Mauro Reini; Melchiorre Casisi. Is the Evolution of Energy System Productive Structures Driven by a Physical Principle? Frontiers in Sustainable Food Systems 2021, 2, 1 .
AMA StyleMauro Reini, Melchiorre Casisi. Is the Evolution of Energy System Productive Structures Driven by a Physical Principle? Frontiers in Sustainable Food Systems. 2021; 2 ():1.
Chicago/Turabian StyleMauro Reini; Melchiorre Casisi. 2021. "Is the Evolution of Energy System Productive Structures Driven by a Physical Principle?" Frontiers in Sustainable Food Systems 2, no. : 1.
The study examines the option of adding a bottom Organic Rankine Cycle (ORC) for energy recovery from an internal combustion engine (ICE) for ship propulsion. In fact, energy recovery from the exhaust gas normally rejected to the atmosphere and eventually from the cooling water circuit (usually rejected to the sea) can significantly reduce the fuel consumption of a naval ICE during its operation. In the paper, different possible bottom ORC configurations are considered and simulated using the Aspen® code. Different working fluids are taken into account, jointly with regenerative and two-temperature levels designs. The energy recovery allowed by each solution is evaluated for different engine load, allowing the identification of the most suitable ORC configuration. For the selected case, the preliminary design of the main heat exchangers is carried out and the off-design performance of the whole combined propulsion plant (ICE + ORC) is evaluated, leading to a preliminary analysis of cost saving during normal ship operation. The results of this analysis show an increase in power output of about 10% and an expected Payback Time of less than 6 years.
Melchiorre Casisi; Piero Pinamonti; Mauro Reini. Increasing the Energy Efficiency of an Internal Combustion Engine for Ship Propulsion with Bottom ORCs. Applied Sciences 2020, 10, 6919 .
AMA StyleMelchiorre Casisi, Piero Pinamonti, Mauro Reini. Increasing the Energy Efficiency of an Internal Combustion Engine for Ship Propulsion with Bottom ORCs. Applied Sciences. 2020; 10 (19):6919.
Chicago/Turabian StyleMelchiorre Casisi; Piero Pinamonti; Mauro Reini. 2020. "Increasing the Energy Efficiency of an Internal Combustion Engine for Ship Propulsion with Bottom ORCs." Applied Sciences 10, no. 19: 6919.
The Gouy-Stodola Theorem is the theoretical basis for allocating irreversibility and for identifying the maximum possible efficiency for any kind of energy conversion system. The well-known theorem is re-obtained in this paper, relaxing the hypothesis about a constant value for temperature and pressure of the reference environment. The equations that have been derived taking into account the variation of reference temperature and pressure show that two additional terms appear in both reversible and irreversible maximum useful work output, besides the well-known terms. These additional terms take into account the potential useful work (exergy) destruction related to the variation of the ambient condition during the considered time interval. In this way the Gouy-Stodola Theorem still holds, but the allocation of exergy destruction is generally different from that calculated in the usual hypothesis of constant temperature and pressure of the reference environment. The Gouy-Stodola Theorem is also used in various textbooks for defining the flow and the non-exergy of a control volume. The same approach is applied in this paper, highlighting the differences and the difficulties related to the variation of the reference pressure and temperature in the reference environment.
Mauro Reini; Melchiorre Casisi. The Gouy-Stodola Theorem and the derivation of exergy revised. Energy 2020, 210, 118486 .
AMA StyleMauro Reini, Melchiorre Casisi. The Gouy-Stodola Theorem and the derivation of exergy revised. Energy. 2020; 210 ():118486.
Chicago/Turabian StyleMauro Reini; Melchiorre Casisi. 2020. "The Gouy-Stodola Theorem and the derivation of exergy revised." Energy 210, no. : 118486.
The paper proposes a comparison of different district integration options for a distributed generation system for heating and cooling in an urban area. The system considered includes several production units located close to the users, a central unit and the district heating and cooling network which can connect all the users to each other and to a central unit, where a cogeneration system and a solar plant can be placed. Thus, each user can be regarded as isolated from the others, satisfying its energy needs by means of an autonomous production unit. Alternatively, it can be connected to the others through the district heating and cooling network. When a district heating and cooling network is included in the design option the synthesis-design and operation problems cannot be solved separately, because the energy to be produced by each production site is not known in advance, as the flows through the district heating and cooling network are not defined. This paper uses a mixed integer linear programming (MILP) methodology for the multi-objective optimization of the distributed generation energy system, considering the total annual cost for owning, operating and maintaining the whole system as the economic objective function, while the total annual CO2 emissions as the environmental objective function. The energy system is optimized for different district integration option, in order to understand how they affect the optimal solutions compared with both the environmental and economic objects.
Melchiorre Casisi; Dario Buoro; Piero Pinamonti; Mauro Reini. A Comparison of Different District Integration for a Distributed Generation System for Heating and Cooling in an Urban Area. Applied Sciences 2019, 9, 3521 .
AMA StyleMelchiorre Casisi, Dario Buoro, Piero Pinamonti, Mauro Reini. A Comparison of Different District Integration for a Distributed Generation System for Heating and Cooling in an Urban Area. Applied Sciences. 2019; 9 (17):3521.
Chicago/Turabian StyleMelchiorre Casisi; Dario Buoro; Piero Pinamonti; Mauro Reini. 2019. "A Comparison of Different District Integration for a Distributed Generation System for Heating and Cooling in an Urban Area." Applied Sciences 9, no. 17: 3521.
The paper deals with the modeling and optimization of an integrated multi-component energy system. On-off operation and presence-absence of components must be described by means of binary decision variables, besides equality and inequality constraints; furthermore, the synthesis and the operation of the energy system should be optimized at the same time. In this paper a hierarchical optimization strategy is used, adopting a genetic algorithm in the higher optimization level, to choose the main binary decision variables, whilst a MILP algorithm is used in the lower level, to choose the optimal operation of the system and to supply the merit function to the genetic algorithm. The method is then applied to a distributed generation system, which has to be designed for a set of users located in the center of a small town in the North-East of Italy. The results show the advantage of distributed cogeneration, when the optimal synthesis and operation of the whole system are adopted, and significant reduction in the computing time by using the proposed two-level optimization procedure.
Melchiorre Casisi; Stefano Costanzo; Piero Pinamonti; Mauro Reini. Two-Level Evolutionary Multi-objective Optimization of a District Heating System with Distributed Cogeneration. Energies 2018, 12, 114 .
AMA StyleMelchiorre Casisi, Stefano Costanzo, Piero Pinamonti, Mauro Reini. Two-Level Evolutionary Multi-objective Optimization of a District Heating System with Distributed Cogeneration. Energies. 2018; 12 (1):114.
Chicago/Turabian StyleMelchiorre Casisi; Stefano Costanzo; Piero Pinamonti; Mauro Reini. 2018. "Two-Level Evolutionary Multi-objective Optimization of a District Heating System with Distributed Cogeneration." Energies 12, no. 1: 114.
The paper deals with the optimization of a distributed urban district heating and cooling cogeneration system. The model is based on a Mixed Integer Linear Program (MILP) and includes a set of micro-cogeneration gas turbines and a district heating network potentially connecting each considered building to all the others. Absorption machines, supplied with cogenerated heat, can be used instead of conventional electrical chiller to face the cooling demand. In addition, a district cooling network can be introduced, independently from the district heating one. The objective of the paper is to obtain the optimal synthesis and operation strategy of the whole system, in terms of Total Annual Cost for owning, maintaining and operating the system. The solution has to specify the kind, the number and the location of cogeneration equipment and absorption machines, the size and the position of district heating and cooling pipelines as well as the optimal operation of each component. The effects of different plant options, comparing cogeneration and tri-generation machines adoption and district heating and cooling pipelines installation, are considered.
Dario Buoro; Melchiorre Casisi; Piero Pinamonti; Mauro Reini. Optimal Lay-Out and Operation of District Heating and Cooling Distributed Trigeneration Systems. Volume 3: Controls, Diagnostics and Instrumentation; Cycle Innovations; Marine 2010, 157 -166.
AMA StyleDario Buoro, Melchiorre Casisi, Piero Pinamonti, Mauro Reini. Optimal Lay-Out and Operation of District Heating and Cooling Distributed Trigeneration Systems. Volume 3: Controls, Diagnostics and Instrumentation; Cycle Innovations; Marine. 2010; ():157-166.
Chicago/Turabian StyleDario Buoro; Melchiorre Casisi; Piero Pinamonti; Mauro Reini. 2010. "Optimal Lay-Out and Operation of District Heating and Cooling Distributed Trigeneration Systems." Volume 3: Controls, Diagnostics and Instrumentation; Cycle Innovations; Marine , no. : 157-166.
This paper deals about the application of MILP for economic optimization of complex cogenerative systems. In particular, it optimizes both the size and operating strategy of CHP systems and the lay-out of micro district heating networks applied to a urban contest. The proposed model considers the possible adoption of a set of micro-cogeneration gas turbines located in different buildings, and of a centralized cogeneration system thus allowing part of the required thermal energy to be produced in a single site. In addition, thermal and photovoltaic panels can be integrated into the system to improve thermal and electrical energy production, respectively. Each site can be connected to the others through district heating micro-grids. Hence thermal energy can be distributed inside the system. A further objective of the paper is to evaluate the effect of different economic support policies on the optimal solution, and to relate the economic effort implied in each support policy with the expected results in terms of CO2 emissions reduction and primary energy savings.
Melchiorre Casisi; Lorenzo Castelli; Piero Pinamonti; Mauro Reini. Effect of Different Economic Support Policies on the Optimal Definition and Operation of a CHP and RES Distributed Generation Systems. Volume 3: Combustion, Fuels and Emissions, Parts A and B 2008, 123 -130.
AMA StyleMelchiorre Casisi, Lorenzo Castelli, Piero Pinamonti, Mauro Reini. Effect of Different Economic Support Policies on the Optimal Definition and Operation of a CHP and RES Distributed Generation Systems. Volume 3: Combustion, Fuels and Emissions, Parts A and B. 2008; ():123-130.
Chicago/Turabian StyleMelchiorre Casisi; Lorenzo Castelli; Piero Pinamonti; Mauro Reini. 2008. "Effect of Different Economic Support Policies on the Optimal Definition and Operation of a CHP and RES Distributed Generation Systems." Volume 3: Combustion, Fuels and Emissions, Parts A and B , no. : 123-130.