Sergio Sibilio

Micro-combined heat and power in residential and light commercial applications

Abstract The cogeneration is worldwide considered as the major option to achieve considerable energy saving with respect to traditional systems. This paper deals with the application of micro-cogeneration (electrical power

Assessment of micro-cogeneration potential for domestic trigeneration

Cogeneration is worldwide considered as the major option to achieve considerable energy saving with respect to traditional systems. This paper deals with the application of micro-cogeneration, Micro-Combined Heat and Power (MCHP) (electrical power &;60;15 kW) to small-scale (residential application) users for the assessment of its use in trigeneration; the state of art of this technology is considered, a test facility designed and built to evaluate the performances of MCHP-Electric Heat Pump (EHP) system itself is described and the Energetic, Economic and Environmental (3-E) analysis in some operation mode to match the users loads is proposed.

Optimum performance of heat engine-driven heat pumps: A finite-time approach

Abstract Classic thermodynamics, assuming the Carnot machine as the upper comparison limit in energy conversion systems analysis, considers thermal equilibrium during heat transfer interactions. Such an assumption requires either infinitely slow cycles or infinitely large heat exchanger surfaces. More realistic limits on the optimal operation of energy systems can be provided by finite-time thermodynamics, which takes into account the constraints represented by finite operation time and limited heat interaction area. This paper focuses on the search for the optimum heating performance of a heat engine-driven heat pump in which the waste engine heat is used for heating purposes. At first, only thermal irreversibilities are considered; then, in order to obtain a more realistic model, the so called “internal” heat leak irreversibilities are taken into account too. Finally, a comparison between the performances of the irreversible model and those of actual plants is carried out.

Experimental analysis of small scale cogenerators based on natural gas fired reciprocating internal combustion engine

The European Union recently established an ambitious target by 2020 that consists of increasing the utilization of renewable energy up to 20%, reducing its overall pollutant emissions to at least 20%, and achieving a primary energy saving of 20% compared to reported 1990 levels. This aim could be reached only with strong effort in different sectors, such as residential, commercial, industry, tertiary, transportation, .... In particular in the European Union a remarkable contribution to energy consumption and CO2 emissions is concentrated in residential and commercial sector. The introduction of more efficient technologies in these sectors could help in achieving the results expected by 2020. An option is given by cogeneration, defined as the combined “production” of electric and/or mechanical and thermal energy starting from single energy source, that could be considered one of the first elements to save primary energy, to avoid network losses and to reduce the greenhouse gas emissions. In particular, our interest will be focused on the microcogeneration (electric power ≤ 15 kW), which represents a valid and interesting application for residential and light commercial users. The energetic, economic and environmental implications due to the use of small scale cogeneration systems were reported, starting by an experimental research activity performed by the authors and other researchers.© 2010 ASME

Cogeneration for Energy Saving in Household Applications

During the last decade, small-scale combined heat and power systems are becoming a viable alternative to conventional power supply and boiler-based heating system in many types of applications. With regard to domestic sector, the use of combined Heat and Power generation on micro scale (< 15 kW electric output), micro-CHP for short, is currently relatively uncommon, but the market availability of gas-fuelled generating equipment, together with a significant number of current R&D projects, confirms the large potential for micro-CHP development, that was up to now limited to niche applications. In this paper attention is paid to the problems derived by the transfer of this technology, well known in the industrial field, to small-scale applications. One of the greatest obstacle is the match between thermal and electric energy outputs of the micro-CHP and the load profiles of end users. Consequently, some energy residential appliances such as dishwasher, clothes washer, water heater, will be considered in the paper, both in their traditional configuration (electricity driven) and in alternative more efficient configurations (thermal and electricity driven). Some energetic and economic analyses are presented. Finally an experimental apparatus set up to study the integration of a micro-CHP system with usual household appliances and heating equipment is shown.

The Micro-cogeneration and Emission Control and Related Utilization Field

Micro-cogeneration is a developed technology aiming to produce electricity and heat close to the final users, with the potential, if designed and operated correctly, to reduce both the primary energy consumption as well as the associated greenhouse gas emissions when compared to traditional energy supply systems based on separate energy production. The distributed nature of this generation technology has the additional advantages of (i) reducing electrical transmission and distribution losses, (ii) alleviating the peak demands on the central power plants, and (iii) diversifying the electrical energy production, thus improving the security of energy supply. Micro-cogeneration devices are used to meet both electrical requirements and heat demands (for space heating and/or hot water production) of a building; they can be also combined with small-scale thermally fed or mechanically/electrically driven cooling systems. Many micro-cogeneration units are already commercialized in different countries (such as Japan, Germany, United Kingdom, etc.) and in recent years several researches have been carried out in order to advance the design, operation, and analysis of this technology. Currently the use of commercial micro-cogeneration units in applications such as hospitals, leisure facilities, hotels, or institutional buildings is well established. The residential cogeneration industry is in a rapid state of development; the market remains not fully mature, but interest in the technology from manufacturers, energy utilities, and government agencies remains strong.

Energy Technologies for Building Supply Systems: MCHP

Micro-cogeneration is an emerging technology with the potential to—if designed and operated correctly—reduce both the primary energy consumption and the associated greenhouse gas emissions, when compared to traditional energy supply systems. The distributed nature of this generation of technology has the additional advantages of (1) reducing electrical transmission and distribution losses; (2) alleviating the peak demands on the central power plants; and (3) diversifying the electrical energy production, thus improving the security of energy supply. The micro-cogeneration devices are used to meeting the electrical and heating demands of buildings for space heating/hot water production, as well as potentially (mainly for temperate and hot climates) absorption/adsorption cooling systems. Currently, the use of commercial micro-cogeneration units in applications such as hospitals, leisure facilities, hotels, or institutional buildings is well established. The residential cogeneration industry is in a rapid state of development and flux, and the market remains undeveloped, but interest in the technologies by manufacturers, energy utilities, and government agencies remains strong.

Gas Driven Micro-Cogenerator Incorporating Heat Pump: Exergetic, Economic and Environmental Analysis

A natural gas-fired micro-cogenerator (MCHP) based on a reciprocating internal combustion engine that drives an electric heat pump (EHP), MCHP/EHP, has been analyzed. It allows a high degree of flexibility in terms of operating conditions, due to the possibility to use the two devices separately supplying electric and thermal (heating and cooling) energy (CCHT, Combined Cooling Heating and Power). The MCHP/EHP is a gas cooling technology that can contribute to optimize the natural gas and electricity consumptions in those countries where the HVAC systems are widespread. In particular, our interest was focused on micro-cogenerators (electric power ≤ 15 kW) at the moment available on the market, based on reciprocating internal combustion engine, that could have a great diffusion in the near future for domestic and light commercial applications. Starting by the results of an intense experimental activity an exergetic, economic and environmental analysis has been carried out to compare the proposed MCHP/EHP system to the conventional one based on separate “production”.Copyright