154,129 research outputs found

    Contribution to Local Landscape Units definition in OTALEX II

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    OTALEX II is the Territorial and Environmental Observatory of Alentejo (Portugal) and Extremadura (Spain), co-financed by POCTEP, developed with the cross-border collaboration of several Portuguese and Spanish bodies. It is composed of a Spatial Data Infrastructure (SDI) created in 2007, SDI-OTALEX (www.ideotalex.eu), which is an exchange platform for geographic information and Webmapping services among project partners. The integration of environmental indicators such as landscape indicators, for the characterization and monitoring of the Alentejo Extremadura area is one of the most relevant components of the project. This paper reports the achievements in defining Local Landscape Units (LLU) for a pilot area of Central Alentejo – the Pardiela river basin. The methodological approach applied Geographic Information System tools to integrate soils, geomorphology and land cover. The land cover map applies the CORINE Land Cover Legend Level 5 to Central Alentejo at a scale of 1 : 10,000. This map contains variables related to vegetation, hydrology (streams and water bodies) and human settlements (buildings, equipment, roads). The validation of the results obtained for LLU with previously defined Landscape Units and potential vegetation mapping confirm the reliability and replicability of the present methodology for similar territories

    Non-continuous and variable rate processes: Optimisation for energy use

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    The need to develop new and improved ways of reducing energy use and increasing energy intensity in industrial processes is currently a major issue in New Zealand. Little attention has been given to optimisation of non-continuous processes in the past, due to their complexity, yet they remain an essential and often energy intensive component of many industrial sites. Novel models based on pinch analysis that aid in minimising utility usage have been constructed here through the adaptation of proven continuous techniques. The knowledge has been integrated into a user friendly software package, and allows the optimisation of processes under variable operating rates and batch conditions. An example problem demonstrates the improvements in energy use that can be gained when using these techniques to analyse non-continuous data. A comparison with results achieved using a pseudo-continuous method show that the method described can provide simultaneous reductions in capital and operating costs

    Minimizing water and energy consumptions in water and heat exchange networks.

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    This study presents a mathematical programming formulation for the design of water and heat exchangers networks based on a two-step methodology. First, an MILP (mixed integer linear programming) procedure is used to solve the water and energy allocation problem regarding several objectives. The first step of the design method involves four criteria to be taken into account., ie, fresh water consumption (F1), energy consumption (F2), interconnection number (F3) and number of heat exchangers (F4). The multiobjective optimization Min [F1, F2] is solved by the so-called ɛ-constraint method and leads to several Pareto fronts for fixed numbers of connections and heat exchangers. The second step consists in improving the best results of the first phase with energy integration into the water network. This stage is solved by an MINLP procedure in order to minimize an objective cost function. Two examples reported in the dedicated literature serve as test bench cases to apply the proposed two-step approach. The results show that the simultaneous consideration of the abovementioned objectives is more realistic than the only minimization of fresh water consumption. Indeed, the optimal network does not necessarily correspond to the structure that reaches the fresh water target. For a real paper mill plant, energy consumption decreases of almost 20% as compared with previous studies

    Area targeting and storage temperature selection for heat recovery loops

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    Inter-plant heat integration across a large site can be achieved using a Heat Recovery Loop (HRL). In this paper the relationship between HRL storage temperatures, heating and cooling utility savings (heat recovery) and total HRL exchanger area is investigated. A methodology for designing a HRL based on a ΔTmin approach is compared to three global optimisation approaches where heat exchangers are constrained to have either the same Number of Heat Transfer Units (NTU), Log-Mean Temperature Difference (LMTD) or no constraints (actual global optimum). Analysis is performed using time averaged flow rate and temperature data. Attention is given to understanding the actual temperature driving force of the HRL heat exchangers compared to the apparent driving force as indicated by the composite curves. The cold storage temperature is also varied to minimise the total heat exchanger area. Results for the same heat recovery level show that the ΔTmin approach is effective at minimising total area to within 5 % of the unconstrained global optimisation approach. The study also demonstrates the efficiency of the ΔT min approach to HRL design compared to the other methods which require considerable computational resources

    Area targeting and storage temperature selection for heat recovery loops

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    Inter-plant heat integration across a large site can be achieved using a Heat Recovery Loop (HRL). In this paper the relationship between HRL storage temperatures, heating and cooling utility savings (heat recovery) and total HRL exchanger area is investigated. A methodology for designing a HRL based on a ΔTmin approach is compared to three global optimisation approaches where heat exchangers are constrained to have either the same Number of Heat Transfer Units (NTU), Log-Mean Temperature Difference (LMTD) or no constraints (actual global optimum). Analysis is performed using time averaged flow rate and temperature data. Attention is given to understanding the actual temperature driving force of the HRL heat exchangers compared to the apparent driving force as indicated by the composite curves. The cold storage temperature is also varied to minimise the total heat exchanger area. Results for the same heat recovery level show that the ΔTmin approach is effective at minimising total area to within 5 % of the unconstrained global optimisation approach. The study also demonstrates the efficiency of the ΔT min approach to HRL design compared to the other methods which require considerable computational resources

    Techno-economic energy models for low carbon business parks

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    To mitigate climate change, global greenhouse gas emissions need to be reduced substantially. Industry and energy sector together are responsible for a major share of those emissions. Hence the development of low carbon business parks by maximising energy efficiency and changing to collective, renewable energy systems at local level holds a high reduction potential. Yet, there is no uniform approach to determine the optimal combination and operation of energy technologies composing such energy systems. However, techno-economic energy models, custom tailored for business parks, can offer a solution, as they identify the configuration and operation that provide an optimal trade-off between economic and environmental performances. However, models specifically developed for industrial park energy systems are not detected in literature, so identifying an existing model that can be adapted is an essential step. In this paper, energy model classifications are scanned for adequate model characteristics and accordingly, a confined number of models are selected and described. Subsequently, main model features are compared, a practical typology is proposed and applicability towards modelling industrial park energy systems is evaluated. Energy system evolution models offer the most perspective to compose a holistic, but simplified model, whereas advanced energy system integration models can adequately be employed to assess energy integration for business clusters up to entire industrial sites. Energy system simulation models, however, provide deeper insight in the system’s operation

    WinGEMS modelling and pinch analysis of a paper machine for utility reduction

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    A multi-ply paper machine process model was developed using WinGEMS and the stream data produced was used to conduct a pinch analysis. The product stream was excluded from the analysis and the composite curves display the enthalpy contained only in the inputs and outputs to the various sections of the paper machine. The pinch point for the overall paper machine was 55.9 C while the minimum hot utility target was 170 MW. Occurrences of cross pinch heat transfer were identified and discussed. Heat recovery options for heating of the fresh water showers, using waste heat streams were investigated. Steam savings of over 14 MW could be achieved by recovering heat from two waste streams that currently go directly to drain with no heat recovery taking place. The use of pinch analysis for utilities targeting under non-continuous conditions was examined. Finally, the feasibility of integrating non-conventional technologies, such as heat storage, is discussed

    Information streams of education content integrative designing at a federal university

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    © 2016 Kirilova and Vlasova.Modern university education is aimed to provide a future expert with knowledge and experience of professional activity in the context of information society development and innovative knowledge-intensive production. At the same time information the teacher should be furnished with to implement own designing activity in the context of new education content formation is getting actual. Such designing is gaining an integrative character and becomes essential in the environment of controlled information streams. The paper reveals the phenomenon of education content integrative designing, features and invariant requirements to its content adequate to current trends of university education development, and ensures the unity and specificity of educational, scientific, production and social spheres of education content implementation realized within the selection of a variable logistic trajectory of its designing. The leading approaches to research the ways of integrative designing were system analysis of dynamic information educational environment and modeling of a logistic structure of information streams of educational purpose. The paper reveals the double-circuit organization of data exchange in the course of education content designing within which internal streams provide disciplinary differentiation, and external streams provide integration of disciplines, training profiles and educational structures. The paper develops subject - subject and subject – object exchange of information between educational organizations and society, between governing structures and divisions, between students and teachers in information educational environment of education content integrative designing. The paper proves that integration of information streams is a key idea to solve problems of timely and high-quality integrative designing of innovative education content. Practical significance of materials from the paper is that on the basis of described procedures the realization of developed functions and established interactions can be transferred to links of the information environment, and exchange of information becomes mediated by information resources and agents of educational purpose. The practical importance consists in the detailed and experimentally approved organization of an integration link regulating information exchanges in the course of designing and educational activity of subjects and agents of educational process
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