Search results for "Heat recovery ventilation"
showing 10 items of 16 documents
Optimisation of Heat Loss through Ventilation for Residential Buildings
2018
This study presents the results of research on heat loss from various types of residential buildings through ventilation systems. Experimental research was done to analyse the effectiveness of ventilation systems of different types and determine the parameters of air discharged via the ventilation ducts. A model of heat loss from the discharge of exhaust air outside through air ducts has since been developed. Experiments were conducted on three experimental systems of building ventilation: gravitational, mechanical, and supply-exhaust ventilation systems with heat recovery. The proposed model dependencies were used to chart the daily fluctuations of the optimum multiplicity of air exchange …
Investigating energy saving potential in a big shopping center through ventilation control
2019
Abstract This paper investigates energy saving measures for the ventilation system of large shopping centers. This kind of buildings is characterized by high yearly energy consumptions, because of the high level of operating hours and the frequent use of obsolete technologies. In the analyzed case studies, three big Do It Yourself (DIY) shops, located in Italy, are considered. Two different approaches are considered, they are aimed at reducing the annual energy consumption for the indoor air exchange of the sales area. The first considered retrofit solution consists in the installation of heat recovery exchangers, reducing the energy demand for the air thermal treatment without changing the…
On interactive multiobjective optimization with NIMBUS® in chemical process design
2005
We study multiobjective optimization problems arising from chemical process simulation. The interactive multiobjective optimization method NIMBUS®, developed at the University of Jyvaskyla, is combined with the BALAS® process simulator, developed at the VTT Technical Research Center of Finland, in order to provide a new interactive tool for designing chemical processes. Continuous interaction between the method and the designer provides a new efficient approach to explore Pareto optimal solutions and helps the designer to learn about the behaviour of the process. As an example of how the new tool can be used, we report the results of applying it in a heat recovery system design problem rela…
Energy performance evaluation of a demo solar desiccant cooling system with heat recovery for the regeneration of the adsorption material
2012
Abstract Since July 2008, a Solar Desiccant Evaporative Cooling (DEC) system has been operating as a test plant at the solar laboratory of the Dipartimento di Energia (ex DREAM) of the University of Palermo. The system is composed of an air handling unit (AHU) designed for ventilation of the laboratory coupled with a radiant ceiling that provides most of the required sensible cooling/heating energy. Flat plate collectors deliver part of the regeneration heat of the desiccant wheel during the summertime and are used for space heating during the wintertime. The system was designed for high humidity loads because of the typical climate conditions at the site and the need to support a radiant c…
Assessing the feasibility of cogeneration retrofit and district heating/cooling networks in small Italian islands
2017
Sustainability of energy supply strategies in small islands has been emerging as a severe issue, due to the large margins for improvement and rationalization of the most frequently adopted solutions. In most of the European islands, large amounts of heat are wasted by the operation of engine-based power plants; conversely, heat is produced by boilers (supplied by liquid fuels) or by electric equipment for a number of different uses, like domestic hot water production or space heating in winter. In this paper a techno-economic analysis is proposed to assess the feasibility of CHP-retrofit of the existing power plants and the possible utilization of the recovered heat to supply, via a distric…
Absorption equipment for energy savings: A case study in Sicily
2013
Abstract This paper considers a feasibility study on the recovery of the reject heat available from an electric utility with two units operating with 120-MW gas turbines; these units have a heat recovery system that feeds the district heating pipeline of an industrial consortium. Thus, feeding the expeller of the absorption equipment installed in a cooling plant for foodstuff stocking represents an opportunity for the feasibility study. This plant operates at both 0 °C and −18 °C. The feasibility study covers two aspects: (1) the technical feasibility of a suitable absorption cooling plant that uses two separate pieces of absorption equipment working with the pair ammonia–water and (2) the …
Simulation model of a molten carbonate fuel cellemicroturbine hybrid system
2011
A Hybrid System based on High Temperature Fuel Cells coupled to a Microturbine allows a high efficiency, low environmental pollution and it may be exploited as a CHP System producing heat and electricity both Grid Connected and Stand Alone; the overall electrical efficiency could reach a very high value (up to 60%) and total efficiency could be over 70% including the contribution due to heat recovery. In the context of wide research activities of ENEA on High Temperature Fuel Cells and Hybrid Systems e that involve materials, system BoP and fuels e a very great effort has been devoted to design and build, in the ENEA Research Centre of “Casaccia”, an experimental Test-Rig based on a Molten …
Thermal analysis and new insights to support decision making in retrofit and relaxation of heat exchanger networks
2011
International audience; Pinch analysis offers a rational framework for identifying energy saving targets and designing efficient heat recovery networks, especially in process industry. Several scientists have contributed to improve and automate the original pinch method over the last decades, increasing its capability to deal with a number of specific issues; the expertise of the analyst, however, remains determinant in achieving optimal results. In this paper a procedure for retrofit of existing networks is proposed, based on an integrate use of several techniques (either existing or innovative). The diagnosis of the existing network and of a "Minimum Energy Requirement" configuration emer…
On the Phase Separation in n-Type Thermoelectric Half-Heusler Materials
2018
Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements. Half-Heusler compounds usually exhibit a high electrical conductivity σ , resulting in high power factors. The main drawback of half-Heusler compounds is their high lattice th…
Optimization of ventilation system in the open office space
2018
The paper presents the results of study into the air parameters in open space offices. As office workers spend about 1/3 of the day in such spaces, it is important to provide them with the right climate comfort, and that is determined, most importantly, by: the temperature and humidity of the air, quality of the air, and the concentration of CO2. Two objects of study were selected - both of them open space facilities, each with a different intensity of use. In the course of study, measurements were taken on the basis of which the distributions of temperature, humidity, and concentrations of CO2 in the entire volume of the space were determined. Also the empirical coefficients of CO2 emissio…