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Extract Air Energy Utilization Using Heat Pump in Buildings with Indoor Swimming Pools
No full textAn annual energy consumption simulation is made for one Latvian mansion with swimming pool hall.
Building has two main parts: living part (with bedrooms, living room, kitchen, and washing rooms),
and a recreation part with 28m² swimming pool, saunas and sports hall.
HVAC system consists of the following elements: heating system with convectors, water-to-water
heat pump system cooling / heating concrete slabs in living part, and centralized mechanical extract,
with natural outside air intake through the window grilles. Air –conditioning in swimming pool is
provided by separate air-handling unit with heat pump - dryer.
In winter the heat pump system heats concrete slabs, utilizing extract air energy through air to water
heat exchanger. In summer living room slabs are cooled, and removed heat is used for the swimming
pool supply-air preheating.
The annual energy consumption simulation is made with DOE 2.1E core based application, using
building’s information model (BIM) for the average Latvian meteorological year. Two BIM’s are
made: for a living part of the mansion and for swimming pool room, using design coefficients for
constructions’ thermal resistance and indoor air parameters.
Simulation results show, that swimming pool room consumes 77 MWh of heating energy per year.
When using heat pump gained energy to preheat swimming pool supply air, annual heat energy
consumption decreases to 62 MWh, which means about 20% saving. The heat pump system annual
average coefficient of performance (COP) according to manufacturer’s data is assumed as 2.5.
Paper results can be used by HVAC engineers and architects for ventilation and air conditioning
design in other multi-purpose buildings with indoor swimming pools
Asymptotic Analysis of Stability of Slightly Curved Two-Phase Shallow Mixing Layers
No full textAsymptotic analysis of stability of slightly curved two-phase mixing layers is performed in the present paper. Small longitudinal variation of the base flow is taken into account in the analysis. Using the method of multiple scales an amplitude equation is derived where the coefficients of the equation depend on the linear stability characteristics of the flow
Urban Development Effect on Passive House Energy Consumption
No full textThe paper describes one of the energy-efficient building concepts – a passive house. In the course of the works there was simulated a multifamily residential house in order to determine its constructive and spatial parameters that would ensure a passive house with energy efficiency consistent to standards. For the building simulation there were applied the climatic data of the capital of Latvia Riga. Initially there was chosen an optimal orientation of the building and maximum theoretical insolation of the building. At the second stage there were studied the external factors – the shade caused by the surrounding buildings and the effect of the building orientation dictated by urban conditions on the previously achieved energy efficiency rating. The results evidence that the layout of window apertures and the change of orientation, as well as shading caused by the surrounding buildings, play a significant role in the rating of the building energy efficiency, nonetheless it does not interfere with achieving the passive house standards
Creep Behaviour of Concrete with Glass Waste Microfiller
No full textEvery year there are several hundred tons of waste glass produced in Latvia. Glass can be re-used as a fine raw material and it presents a possibility to save natural, non-renewable materials. The use of glass powder in concrete production can make the construction industry more environmentally friendly. This paper examines the possibility of using glass powder as cement replacement in a new type of concrete. In the experiment, cement was partially (20% and 40%) replaced with glass powder. The long-term deformation (creep) of this new concrete was monitored. Three different concrete mixtures were batched. Specimens of 20% and 40% cement replacement were compared with the specimens made of standard concrete. The samples were tested in two extreme conditions: in one case they were kept in 100% humidity ensured by preventing the desiccation of the concrete, and in the other case samples were air-dried by preventing them from becoming wet. Compression strength and modulus of elasticity of 7 and 28 days old cubic samples was determined
Using Fuzzy Unordered Rule Induction Algorithm for Cancer Data Classification
No full textThis paper studies the use of fuzzy logic in analysis and classification of bioinformatics data. The specific
character of the bioinformatics data, the large number of attributes and the corresponding small number of records,
asks for methods that can process such data and induce comprehensible and easily interpretable IF-THEN
classification rules. Applied experiments were performed using Breast cancer, Prostate cancer, Gastric cancer, Gastric
intestinal disease and Healthy donor data sets using Fuzzy Unordered Rule Induction Algorithm (FURIA). The study
also describes the working processes of FURIA algorithm. To test the classification results of the aforementioned data
sets additional experiments were carried out using bioinformatics data sets frequently used in literature. The paper also
gives conclusions about the parameters that influence classification results (by either increasing or decreasing the
accuracy) or are neutral to classification results
Energy Efficient Use of Robotics in the Automobile Industry
No full textThis paper summarizes various methods of the energy efficient use of medium and high payload industrial robots. Approaches and according savings potential are evaluated for methods like intelligent brake management - release time and power reduction, the temporal storage of the robot’s kinetic energy with capacitive energy buffer of controller’s DCBus, the energy exchange among robot controllers is proposed. Strategic usage alternatives like robot choice, shutdown during the production-free time and setting into a particular standby mode are compared. The energy saving potentials per each method are estimated according to real body-shop production characteristics
Flexural Modulus Identification of Thin Polymer Sheets
No full textThe method of determination of the flexural Young’s modulus is based on a solution to the problem of compression of a thin-walled cylindrical specimen by two parallel planes (TWCS method). This method was employed to calculate the flexural modulus for PET polymer compositions. The flexural modules received by TWCS method were verified by comparing the experimentally measured eigenfrequencies by Polytec vibrometer with numerical results from ANSYS progra
Towards the Refinement of Topological Class Diagram as a Platform Independent Model
No full textIn this paper a refinement process of topological class diagram is presented. The refinement process is aimed to lower the abstraction level of the initial topological diagram which is obtained from the topological functioning model. Topological functioning model uses mathematical foundations that holistically represent complete functionality of the problem and application domains. By lowering abstraction level of the topological class diagram, it gets additional information which is needed during the software development and maintenance phases. The refinement process consists of six steps. As a result of applying refinement process, a rich topological class diagram with lower abstraction level is obtained. The refinement process is a part of topological modeling approach and it is shown in the context of laundry business system software development project. By applying topological modeling approach it is possible to enable computation independent model creation in a formal way and to enable transformation from it to the platform independent model
Assessment of Spatially-Reinforced Carbon Composites Exfoliation after a Low-Speed Impact
No full textA method of evaluation of composite materials damage after a low-speed impact. Mechanical properties of six types of carbon-carbon composite materials have been investigated under compression, lateral bending and shift before and after the impact action. Obtained results were analyzed and the proposed method acceptability was evaluated. FE calculation was performed to determine the interrelation of impact energy and the size of a zone of possible exfoliation and stress intensity
Useful Lifetime and Rational Replacement of Power Transformers
No full textThis paper presents main ideas of power transformers maintenance during lifetime and its rational replacement which is based on resolve of technical condition. Replacement of power transformers always affined with costs and requires financial supply. The recalculation of energy systems nominal value, i.e. power of transformers, is following too. There are many affected nuances