Fair heat distribution under deficits in district heating networks

In order to improve the energy efficiency in district heating networks and the comfort of their customers, these networks need to overcome the problem of unfair heat distribution under heat deficits. This paper introduces a new strategy to achieve this thermal fairness objective: it is low-cost in terms of communication and computation. The proposed approach is illustrated on a simulation example.Comment: 6 pages, 5 figures, submitted to IEEE L-CSS and CDC 202

A Three-Step Methodology to Improve Domestic Energy Efficiency

Increasing energy prices and the greenhouse effect lead to more awareness of energy efficiency of electricity supply. During the last years, a lot of technologies have been developed to improve this efficiency. Next to large scale technologies such as windturbine parks, domestic technologies are developed. These domestic technologies can be divided in 1) Distributed Generation (DG), 2) Energy Storage and 3) Demand Side Load Management. Control algorithms optimizing a combination of these techniques can raise the energy reduction potential of the individual techniques. In this paper an overview of current research is given and a general concept is deducted. Based on this concept, a three-step optimization methodology is proposed using 1) offline local prediction, 2) offline global planning and 3) online local scheduling. The paper ends with results of simulations and field tests showing that the methodology is promising.\u

Demand side management in district heating systems by innovative control

Demand side management can be successfully applied to district heating systems for shaving thermal peaks. Peak shaving allows increasing share of convenient and less pollutant sources (waste heat, cogeneration and renewables) and enabling further building connections without modifying the pipelines. Demand side management in district heating is mainly done by shifting the load. Another interesting option consists in adjusting the substation regulation strategy; this approach not affects the heating schedule. This paper aims at analysing the opportunities for peak shaving using an innovative regulation strategy in the district heating substations, by controlling with a building model the effects on the indoor comfort conditions. The regulation strategy adopted is the Differential of Return Temperatures (DRT), that includes a constraint on the cold outlet section of the heat exchanger. This paper shows that thermal peak of building demand reducing on average of 15% by using the DRT regulation. Considering an entire distribution network, taking into account its thermal dynamics, the total peak request can be shaved of about 24%. Setting of the DRT regulation strategy has been shown being crucial for achieving satisfying peak shaving without compromising the indoor comfort conditions

Short-term Self-Scheduling of Virtual Energy Hub Plant within Thermal Energy Market

Multicarrier energy systems create new challenges as well as opportunities in future energy systems. One of these challenges is the interaction among multiple energy systems and energy hubs in different energy markets. By the advent of the local thermal energy market in many countries, energy hubs' scheduling becomes more prominent. In this article, a new approach to energy hubs' scheduling is offered, called virtual energy hub (VEH). The proposed concept of the energy hub, which is named as the VEH in this article, is referred to as an architecture based on the energy hub concept beside the proposed self-scheduling approach. The VEH is operated based on the different energy carriers and facilities as well as maximizes its revenue by participating in the various local energy markets. The proposed VEH optimizes its revenue from participating in the electrical and thermal energy markets and by examining both local markets. Participation of a player in the energy markets by using the integrated point of view can be reached to a higher benefit and optimal operation of the facilities in comparison with independent energy systems. In a competitive energy market, a VEH optimizes its self-scheduling problem in order to maximize its benefit considering uncertainties related to renewable resources. To handle the problem under uncertainty, a nonprobabilistic information gap method is implemented in this study. The proposed model enables the VEH to pursue two different strategies concerning uncertainties, namely risk-averse strategy and risk-seeker strategy. For effective participation of the renewable-based VEH plant in the local energy market, a compressed air energy storage unit is used as a solution for the volatility of the wind power generation. Finally, the proposed model is applied to a test case, and the numerical results validate the proposed approach

Air Force Institute of Technology Research Report 2001

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, and Engineering Physics

Redesign Support Framework for Complex Technical Processes

Els processos industrials requereixen avaluacions periòdiques per a verificar la seva correcta operació en termes tècnics i econòmics. Aquestes avaluacions són necessàries a causa de els canvis en els mercats i en la legislació ambiental i de seguretat. Per a satisfer aquestes demandes és necessari investigar les alternatives dels processos que permetin l'ús òptim dels recursos existents amb la mínima inversió econòmica possible. Aquesta tasca es coneix com redisseny, que és un procediment per a determinar possibles canvis en un procés existent per a millorar-lo pel en alguna mètrica, tal com econòmica, ambiental, de seguretat, etc. En aquesta tesi es proposa un marc d'ajuda al redisseny per a processos tècnics. Aquest marc fa ús d'una representació jeràrquica de models múltiples del procés que es re dissenyarà en conjunció amb un motor que raonament basat en casos per a ajudar a decidir quins elements del procés han de ser modificats. El marc consisteix en quatre etapes principals: adquisició de la descripció del disseny, identificació de candidats, generació d'alternatives, i adaptació i avaluació d'alternatives.El procés original es modela jeràrquicament emprant conceptes de mitjans-fins i parts-tot. Així el coneixement sobre el comportament, l'estructura, la funció i l'objectiu de cadascuna de les parts del procés es genera i s'emmagatzema automàticament. Donat les noves especificacions o requisits que el procés ha de satisfer, el sistema troba les parts del procés que ha de ser redissenyades. S'utilitza una llibreria de casos per a obtenir seccions alternatives del procés que es puguin adaptar per a substituir parts del procés original. Per tant, el marc proposat permet modelar el procés, identificar els components de procés viables a redissenyar, obtenir components alternatius i finalment adaptar aquests components alternatius en el procés original. Aquest procediment es pot veure com activitat d'enginyeria inversa on es generen models abstractes en diversos nivells a partir d'una descripció detallada d'un procés existent per a reduir la seva complexitat. El marc ha estat implementat i provat en el domini d'Enginyeria Química.Los procesos industriales requieren evaluaciones periódicas para verificar su correcta operación en términos técnicos y económicos. Estas evaluaciones son necesarias debido a los cambios en los mercados y en la legislación ambiental y de seguridad. Para satisfacer estas demandas es necesario investigar las alternativas de los procesos que permitan el uso óptimo de los recursos existentes con la mínima inversión económica posible. Esta tarea se conoce como rediseño, que es un procedimiento para determinar posibles cambios en un proceso existente para mejorarlo con respecto a alguna métrica, tal como económica, ambiental, de seguridad, etc.En esta tesis se propone un marco de ayuda al rediseño para procesos técnicos. Este marco emplea una representación jerárquica de modelos múltiples del proceso que se rediseñará en conjunción con un motor que razonamiento basado en casos para ayudar a decidir qué elementos del proceso deben ser modificados. El marco consiste en cuatro etapas principales: adquisición de la descripción del diseño, identificación de candidatos, generación de alternativas, y adaptación y evaluación de alternativas. El proceso original se modela jerárquicamente empleando conceptos de medios-fines y partes-todo. Así el conocimiento sobre el comportamiento, la estructura, la función y el objetivo de cada una de las parte del proceso se genera y se almacena automáticamente. Dado las nuevas especificaciones o requisitos que el proceso debe satisfacer, el sistema encuentra las partes del proceso que debe ser rediseñadas. Se utiliza una librería de casos para obtener secciones alternativas del proceso que se puedan adaptar para sustituir partes del proceso original. Por lo tanto, el marco propuesto permite modelar el proceso, identificar los componentes de proceso viables a rediseñar, obtener componentes alternativos y finalmente adaptar estos componentes alternativos en el proceso original. Este procedimiento se puede ver como actividad de ingeniería inversa donde se generan modelos abstractos en diversos niveles a partir de una descripción detallada de un proceso existente para reducir su complejidad. El marco ha sido implementado y probado en el dominio de Ingeniería Química.Industrial processes require periodic evaluations to verify their correct operation, both in technical and economical terms. These evaluations are necessary due to changes in the markets, and in safety and environmental legislation. In order to satisfy these demands it is necessary to investigate process alternatives that allow the optimal use of existing resources with the minimum possible investment. This task is known as redesign, which is a procedure to determine possible changes to an existing process in order to improve it with respect to some metric, such as economical, environmental, safety, etc.A redesign support framework for technical processes is proposed in this thesis. This framework employs a multiple-model hierarchical representation of the process to be redesigned together with a case-based reasoning engine that helps to decide which elements of the process should be modified. The framework consists of four main stages: acquisition of the design description, identification of candidates, generation of alternatives, and adaptation and evaluation of alternatives.The original process is modelled hierarchically exploiting means-end and part-whole concepts, and thus knowledge about the behaviour, structure, function and intention of each part of the process is automatically generated and stored. Given the new specifications or requirements that the process must fulfil, the system finds the parts of the process which must be redesigned and a case library is used to obtain alternative process sections which can be adapted to substitute parts of the original process. Therefore, the proposed framework allows to model the process, to identify process components suitable for redesign, to obtain alternative components, and finally, to adapt these components into the original process. This procedure can be seen as a reverse engineering activity where abstract models at different levels are generated from a detailed description of an existing process to reduce its complexity. The framework has been implemented and tested on the Chemical Engineering domain.Postprint (published version