Application of new measurement techniques and strategies to measure ammonia emissions from agricultural activities

Agriculture is the main contributor to the ammonia emissions in the Netherlands. In order to comply with the ammonia emission reduction assigned to the Netherlands, new techniques have been implemented to reduce the ammonia emissions from animal houses, and after application of slurry into the field

Free-energy functional for freezing transitions: Hard sphere systems freezing into crystalline and amorphous structures

A free-energy functional that contains both the symmetry conserved and symmetry broken parts of the direct pair correlation function has been used to investigate the freezing of a system of hard spheres into crystalline and amorphous structures. The freezing parameters for fluid-crystal transition have been found to be in very good agreement with the results found from simulations. We considered amorphous structures found from the molecular dynamics simulations at packing fractions $\eta$ lower than the glass close packing fraction $\eta_{J}$ and investigated their stability compared to that of a homogeneous fluid. The existence of free-energy minimum corresponding to a density distribution of overlapping Gaussians centered around an amorphous lattice depicts the deeply supercooled state with a heterogeneous density profile

On incorporating uncertainty analysis in abstract building performance simulation tools

Building Performance Simulation (BPS) is a powerful measure to educate the building design process. However, its use in practice is too large extends limited to the detailed design stage dedicated to the code compliance analysis of worked out design proposals. BPS is not much used to support the conceptual design stage (CDS). To date BPS – tools are regarded as pure analysis tools, which do not provide design information. It is hypothesized that, when integrating uncertainty analysis techniques to existing BPS – tools (incremental research approach) valuable design information can be provided. The paper gives an update on the process to integrate an uncertainty assessment capability to a tool specifically developed to support the conceptual design stage. The resulting prototype should be capable of providing information about the deviation of specific design parameters (simulation output) based on the uncertainties of the building concept specification (simulation input). In addition to the total uncertainties, the results also indicate sensitivities of the design parameters as a result of the concept specification variation. This paper describes an approach to add extra-capabilities to legacy simulation tools and presents a comparison of uncertainties and total sensitivities calculated with one detailed design analysis (DDA) tool, IES, and one conceptual design analysis (CDA) tool , LEA. The main focus was herby the representation of material properties and its impact on the model uncertainty

On incorporating uncertainty analysis in abstract building performance simulation tools

Building Performance Simulation (BPS) is a powerful measure to educate the building design process. However, its use in practice is too large extends limited to the detailed design stage dedicated to the code compliance analysis of worked out design proposals. BPS is not much used to support the conceptual design stage (CDS). To date BPS – tools are regarded as pure analysis tools, which do not provide design information. It is hypothesized that, when integrating uncertainty analysis techniques to existing BPS – tools (incremental research approach) valuable design information can be provided. The paper gives an update on the process to integrate an uncertainty assessment capability to a tool specifically developed to support the conceptual design stage. The resulting prototype should be capable of providing information about the deviation of specific design parameters (simulation output) based on the uncertainties of the building concept specification (simulation input). In addition to the total uncertainties, the results also indicate sensitivities of the design parameters as a result of the concept specification variation. This paper describes an approach to add extra-capabilities to legacy simulation tools and presents a comparison of uncertainties and total sensitivities calculated with one detailed design analysis (DDA) tool, IES, and one conceptual design analysis (CDA) tool , LEA. The main focus was herby the representation of material properties and its impact on the model uncertainty

Performance prediction of buildings with responsive building elements challenges and solutions

Modelling and simulation can play an important role for design support and product development of responsive building elements (RBEs). There is, however, limited guidance on how to model such adaptable construction elements in an appropriate way. This paper investigates two different strategies for representing the dynamic aspects of RBEs using whole-building performance simulation tools. Simulations are performed for two case studies: (i) a coating with variable emissivity/absorptivity properties, (ii) a storage wall with switchable insulation. The results show that a simplified simulation strategy is not always capable of accurately capturing the relevant physical phenomena in RBEs. Especially when thermal storage effects are involved, the adaptation needs to take place during simulation run-time, to prevent significant errors in the results

Performance prediction of buildings with responsive building elements challenges and solutions

Modelling and simulation can play an important role for design support and product development of responsive building elements (RBEs). There is, however, limited guidance on how to model such adaptable construction elements in an appropriate way. This paper investigates two different strategies for representing the dynamic aspects of RBEs using whole-building performance simulation tools. Simulations are performed for two case studies: (i) a coating with variable emissivity/absorptivity properties, (ii) a storage wall with switchable insulation. The results show that a simplified simulation strategy is not always capable of accurately capturing the relevant physical phenomena in RBEs. Especially when thermal storage effects are involved, the adaptation needs to take place during simulation run-time, to prevent significant errors in the results

Weather data around the world for design of field hospital HVAC

Field hospital (FH) is a military mobile complex to be deployed in almost any climate around the world. Heating, ventilation and air-conditioning (HVAC) system for the Czech Republic FH units is being redesigned. Computer simulation software will be used for the design of HVAC under variety of specific outdoor conditions. Simulation software requires weather data to calculate energy balance of buildings and HVAC systems. Currently there are several weather data sets available for this purpose. All contain weather data but they may differ significantly. Therefore they should be carefully selected prior to their use. Even though a lot of databases are available, there is poor access to proper data outside of U.S., Western Europe and Japan, and in non-typical regions in terms of simulation exercises (i.e. developing countries). This paper reviews accessible weather data files and suggests which weather data should be used for design and long-term performance analysis of FH HVAC system in various non-typical geographical locations around the world

Performance prediction of advanced building controls in the design phase using ESP-r, BCVTB and Matlab

In this paper, we present a new simulation-based approach with capabilities for analysing the impact of advanced control strategies on building performance during the building design phase. This environment consists of ESP-r as building simulation tool, Matlab as software for advanced building controllers and BCVTB as middleware for data exchange per time step between the two programs. After describing the implementation details, we illustrate usability of the design support environment in a case study. This application example demonstrates model predictive control of a building with a thermally activated floor and solar shading. Furthermore, we show the use of explicit state initialization in ESP-r and a method to include uncertain weather predictions in the controller