Energy demand profiles assessment at district scale: A stochastic approach for a block of buildings demand profiles generation

A methodology, based on the concept of reference building models, was developed and applied in order to provide reliable demand profiles for a block of buildings. A block of buildings in Turin was taken as a case study. An engineering bottom-up approach was developed. A reference building was chosen and calibrated with metered data. Various simulation scenarios were developed and a parametric analysis was carried out. Seasonal heating profiles were generated for the reference building. The parametric analysis indicated the small dispersion of the heating profiles for the various scenarios. A database containing the building's heating profiles was created

Design of a low-temperature solar heating system based on a slurry Phase Change Material (PCS)

Flat-plate solar thermal collectors are the most common devices used for the conversion of solar energy into heat. Water-based fluids are frequently adopted as heat carriers for this technology, although their efficiency is limited by certain thermodynamic and heat storage constraints. Latent heat, which can be obtained from microencapsulated Phase Change Slurry (mPCS) – that is a mixtures of microencapsulated Phase Change Materials (mPCM), water and surfactants – is an innovative approach that can be used to overcome some of the aforementioned limitations. The viscosity of these fluids is similar to that of water, and, as a result, they can be pumped easily. Some of the thermo-physical and rheological properties and the material behaviour of flat-plate solar thermal collectors with an mPCS as the heat carrier fluid are analysed in the present work. Solar thermal systems filled with an mPCS are proposed and a prototypal system is presented. The possible advantages and drawbacks of this technology are also discussed

Potentialities of a Low Temperature Solar Heating System Based on Slurry Phase Change Materials (PCS)

AbstractFlat-plate solar thermal collectors are the most common devices to convert solar energy into heat. Water-based fluids are commonly adopted as heat carrier for this technology, although their efficiency is limited by some thermodynamic and heat storage constraints. To overcome some of these limitations, an innovative approach is the use of latent heat, which can be available by means of microencapsulated slurry PCMs (mixtures of microencapsulated Phase Change Materials, water and surfactants). The viscosity of these fluids is similar to that of water and they can be easily pumped. In the present work, some of the thermo-physical and rheological properties and material behaviour that interest flat-plate solar thermal collectors with slurry PCM as the heat carrier fluid are analysed. Concepts of solar thermal systems filled with a slurry phase change material are proposed and a prototypal system is presented. Possible advantages and drawbacks of this technology are also discussed

Energy demand profile generation with detailed time resolution at an urban district scale: A reference building approach and case study

The energy demand in urban areas has increased dramatically over the last few decades because of the intensive urbanization that has taken place. Because of this, the European Union has introduced directives pertaining to the energy performance of buildings and has identified demand side management as a significant tool for the optimization of the energy demand. Demand side management, together with thermal energy storage and renewable energy technologies, have mainly been studied so far at a building scale. In order to study and define potential demand side management strategies at an urban scale, an integrated urban scale assessment needs to be conducted. DiDeProM, a model that can be used to generate detailed thermal energy demand profiles, at an urban district scale, has been developed in the current study. It is a bottom-up engineering model, based on samples of the representative building technique. A parametric analysis of the important variables of building energy performance at an urban scale has then been carried out. This has generated a database of normalized thermal energy demand profiles with an hourly time resolution. The final step of the process includes the generation of a detailed overall thermal energy demand profile at an urban district scale. DiDeProM was applied to a block of buildings in Turin (Italy) as a case study. After the calibration of the simulation model on real monitored data, a parametric analysis on 300 scenarios for a reference building was conducted, generating a database of seasonal thermal heating energy demand profiles with hourly time steps. An average hourly heating profile was generated from this database according to a specific aggregation approach. The DiDeProM application indicated that the model works properly at the scale of a typical small block of buildings, and it is able to generate a total thermal energy demand profile, with detailed time resolution, at an urban district scale. These profiles will be used to create demand side management strategies that will integrate thermal energy storage and renewable energy technologies at a district scale

A Method for Simultaneous Optimization of Energy Demand and Energy Supply in Buildings

This paper deals with simultaneous optimization of the building energy performance from both building and system design points of view. The majority of the researches conducted on building energy demand reduction and energy supply optimization, treat demand and supply sides separately. Firstly, the demand side parameters are analyzed for demand reduction and then the most suitable configuration for the primary energy conversion is investigated. The relationship between the building energy demand and supply may not be well understood when they are analysed sequentially instead of simultaneously. This paper investigates the potentialities of an integrated building demand-supply energy optimization method that will provide a solution to whole building energy efficiency problem. The method is based on the Extended Building Energy Hub (EBEH) concept which is an evolution of the Building Energy Hub (BEH) method. In the BEH approach the vector of energy inputs, the energy supply fluxes, is related to the vector of energy outputs, the energy demand, by a coupling matrix. The coefficients of this matrix are functions of the efficiency of the various energy conversion systems and of the distribution of energy fluxes onto the energy converters. In the EBEH method, demand side building design parameters will also be included to coupling matrix and will be evaluated together with primary energy options. This way the for instance, demand side parameters (U values, window-to-wall ratio, etc.) will be contrasted to the opportunity to use solar energy for electricity production in terms of primary energy savings and the optimum configuration will be calculated. The paper introduces the basic principles of this approach. Moreover, a preliminary practical demonstration is developed through the application of a simplified procedure to a case study of an existing building