Heating ventilation and air conditioning (HVAC) systems represent an important amount of the total energy use in office buildings, accounting for near 30%. Moreover, in countries affected by extreme climates HVAC syst...
详细信息
Heating ventilation and air conditioning (HVAC) systems represent an important amount of the total energy use in office buildings, accounting for near 30%. Moreover, in countries affected by extreme climates HVAC systems' contribution to energy demand increases up to 50%. Therefore, the automation of energy efficient strategies that act on the Building Energy Management System (BEMS) in order to improve building energy use becomes increasingly relevant. This paper delves into the devising of a novel HVAC optimization framework, coined as Next24h-Energy, which consists on a two-way communication system, an enhanced database management system and a set of machine learning algorithms based on random forest (RF) regression techniques mainly focused on providing an energy-efficient predictive control of the HVAC system. Therefore, the proposed framework achieves optimal HVAC ON/OFF and mechanical ventilation (MV) schedule operation that minimizes the energy consumption while keeps the building between a predefined indoor temperature margins. Simulation results assess the performance of the proposed Next 24 h-Energy framework at a real office building named Mikeletegi 1 (M1) in Donostia-San Sebastian (Spain) yielding to excellent results and significant energy savings by virtue of its capability of adapting the parameters that control the HVAC schedule in a daily basis without affecting user comfort conditions. Specifically, the energy reduction for the test period is estimated in 48% for the heating and 39% for the cooling consumption. (C) 2017 Elsevier B.V. All rights reserved.
Ship designing is a complex process, as the ship itself is a complex, technical multi-level object which operates in the air/water boundary environment and is exposed to the action of many different external and inter...
详细信息
Ship designing is a complex process, as the ship itself is a complex, technical multi-level object which operates in the air/water boundary environment and is exposed to the action of many different external and internal factors resulting from the adopted technical solutions, type of operation, and environmental conditions. A traditional ship design process consists of a series of subsequent multistage iterations, which gradually increase the design identification level. The paper presents problems related to the design of a small untypical vessel with the aid of variant methodology making use of optimisation algorithms. The computer-aided design methodology has been developed which does not need permanent reference to already built real ships and empirical-statistical relations. Possibilities were indicated for integrating together early design stages, and parallel designing of hull shape and parameters.
Minimisation of power consumption is the primary target of the most commonly used procedures and strategies for the capability prediction of DP systems installed on floating objects and, therefore, dealing with an hug...
详细信息
Minimisation of power consumption is the primary target of the most commonly used procedures and strategies for the capability prediction of DP systems installed on floating objects and, therefore, dealing with an huge amount of limitations or restrictions that should be satisfied at the same time for different operating conditions. However, in the particular case of the "extreme limit prediction" for a considered system, other factors assume a prominent importance instead of fuel consumption, like the ability to use all the available power to keep the position in heavy weather conditions. When the maximum operating cases for a vessel are analysed, other effects like thruster-hull interaction and thruster-thruster interaction are rarely considered. To take into account the above-mentioned effects, different thrust allocation strategies were studied and implemented in a capability prediction suite. In this paper a new allocation philosophy is presented, with the aim of maximising the DP capability of a vessel operating in heavy whether conditions. An application of the procedure on two existing offshore vessels is also considered to highlight the effects of different allocation strategies and of the interaction effects on the resulting DP capability in terms of "operational rosettes". (C) 2016 Elsevier Ltd. All rights reserved.
This paper presents a model-driven approach to developing pervasive computing applications that exploits design-time information to support the engineering of planning and optimisation algorithms that reflect the pres...
详细信息
ISBN:
(纸本)9781424495290
This paper presents a model-driven approach to developing pervasive computing applications that exploits design-time information to support the engineering of planning and optimisation algorithms that reflect the presence of uncertainty, dynamism and complexity in the application domain. In particular the task of generating code to implement planning and optimisation algorithms in pervasive computing domains is addressed. We present a layered domain model containing a set of object-oriented specifications for modelling physical and sensor/actuator infrastructure and state-space information. Our model-driven engineering approach is implemented in two transformation algorithms. The initial transformation parses the domain model and generates a planning model for the application being developed that encodes an application's states, actions and rewards. The second transformation parses the planning model and selects and seeds a planning or optimisation algorithm for use in the application. We present an empirical evaluation of the impact of our approach on the development effort associated with a pervasive computing application from the Intelligent Transportation Systems (ITS) domain, and provide a quantitative evaluation of the performance of the algorithms generated by the transformations.
The relationship between the well known competitive torque density and less competitive power factor of reluctance synchronous machines is investigated. The study consists of a multi-objective design optimisation impl...
详细信息
The aim of this work is to capture current practices in the use of computational optimisation in UK engineering companies and identify the current challenges and future needs of the companies. To achieve this aim, a s...
详细信息
The aim of this work is to capture current practices in the use of computational optimisation in UK engineering companies and identify the current challenges and future needs of the companies. To achieve this aim, a survey was conducted from June 2013 to August 2013 with 17 experts and practitioners from power, aerospace and automotive Original Equipment Manufacturers (OEMs), steel manufacturing sector, small-and medium-sized design, manufacturing and consultancy companies, and optimisation software vendors. By focusing on practitioners in industry, this work complements current surveys in optimisation that have mainly focused on published literature. This survey was carried out using a questionnaire administered through face-to-face interviews lasting around 2 h with each participant. The questionnaire covered 5 main topics: (i) state of optimisation in industry, (ii) optimisation problems, (iii) modelling techniques, (iv) optimisation techniques, and (v) challenges faced and future research areas. This survey identified the following challenges that the participant companies are facing in solving optimisation problems: large number of objectives and variables, availability of computing resources, data management and data mining for optimisation workflow, over-constrained problems, too many algorithms with limited help in selection, and cultural issues including training and mindset. The key areas for future research suggested by the participant companies are as follows: handling large number of variables, objectives and constraints particularly when solution robustness is important, reducing the number of iterations and evaluations, helping the users in algorithm selection and business case for optimisation, sharing data between different disciplines for multi-disciplinary optimisation, and supporting the users in model development and post-processing through design space visualisation and data mining. (C) 2015 CIRP.
The relationship between the well known competitive torque density and less competitive power factor of reluctance synchronous machines is investigated. The study consists of a multi-objective design optimisation impl...
详细信息
ISBN:
(纸本)9781479979424
The relationship between the well known competitive torque density and less competitive power factor of reluctance synchronous machines is investigated. The study consists of a multi-objective design optimisation implementing a weighted factor optimisation technique. The investigation was carried out by implementing a complete machine model in the optimisation, with varying machine pole number and flux barrier number combinations. Determination of the weighting of this specific parameter relationship enables the designer to select an optimum multi-objective relationship during optimisation. A specific machine was selected for analysis, then analysed and manufactured for validation of simulation results.
An inviscid model for complete axial flow turbomachinery is adopted, which replaces the blades with throughflow surfaces. The main effects of the real blades on the flow are modelled by blade forces. The inverse metho...
详细信息
An inviscid model for complete axial flow turbomachinery is adopted, which replaces the blades with throughflow surfaces. The main effects of the real blades on the flow are modelled by blade forces. The inverse method predicts the axisymmetric flow field and throughflow surface geometry for a specified distribution of azimuthal inviscid force. This quantity drives the meridional distribution of rotor shaft power. Euler equations are solved by an implicit upwind finite-volume scheme. The time-marching computation includes an evolutionary equation for each throughflow surface, which is solved by implicit finite differences. Standard optimisation algorithms are used to find distributions of azimuthal force that minimise some sample cost functions. The optimal blade shapes are given by the corresponding geometrical solutions of the inverse problem. Since the cost function evaluation is reduced to an inviscid two-dimensional computation, the entire process is significantly less time-consuming than those based on three-dimensional CFD solvers.
Welded frame structures are often subject to unintended distortions due to the thermal joining process. In order to precisely quantify and reduce the distortion of welded frame structures using Finite Element (FE) sim...
详细信息
Welded frame structures are often subject to unintended distortions due to the thermal joining process. In order to precisely quantify and reduce the distortion of welded frame structures using Finite Element (FE) simulation, a fast and reliable method is required, especially for industrial applications. This paper presents a methodical, simulation based and time optimised framework for the prediction of appropriate process parameters for minimal component distortion of complex welded frame structures by means of e.g. a variation of the process parameters or the weld seam sequences. To achieve a minimal distortion of the final structure, different optimisation algorithms will be used in combination with a database. (C) 2014 Elsevier B.V.
Welded frame structures are often subject to unintended distortions due to the thermal joining process. In order to precisely quantify and reduce the distortion of welded frame structures using Finite Element (FE) sim...
详细信息
Welded frame structures are often subject to unintended distortions due to the thermal joining process. In order to precisely quantify and reduce the distortion of welded frame structures using Finite Element (FE) simulation, a fast and reliable method is required, especially for industrial applications. This paper presents a methodical, simulation based and time optimised framework for the prediction of appropriate process parameters for minimal component distortion of complex welded frame structures by means of e.g. a variation of the process parameters or the weld seam sequences. To achieve a minimal distortion of the final structure, different optimisation algorithms will be used in combination with a database.
暂无评论