Heat setting system development of bridge floor surface using low temperature geothermal energy

Multilevel transport interchanges play a decisive role in the road infrastructure both throughout the world and in Russia. Significant problems of the safe operation of multi-level highways in the general metropolitan traffic system and the country territory, in general, are associated with the need to thoroughly clear them of snow and ice during winter and off-season periods. The simplest, most obvious, and historically proven non-mechanical ice control method is using the chemical reagents mixtures. Despite the fact that the quality of the original anti-ice chemical products is constantly being improved, the reagents composition is updating, the target operation remains unchanged — a decrease in the ice and snow melting temperature point. Unfortunately, in the process of melting with heavy snowfall, the concentration and, accordingly, the brine viscosity increases, leading to «oiling» of the asphalt pavement, thereby worsening the already difficult situation on the road. One of the attractive ways to keep the roadway in proper condition is to heat it to get rid of ice. Direct heating methods such as central heating or electric heating are too costly and economically unfeasible. It seems promising to use low-temperature geothermal energy, which will significantly reduce energy costs and increase the transport projects’ economic attractiveness. This work is devoted to the study of the practical applicability of the bridge floor surface heat setting technology using low-temperature geothermal energy as part of the «Best available technologies» concept implementation in accordance with GOST R 56828.15-2016 in terms of infrastructure facilities energy efficiency. Based on the work results, the authors provide the study results and numerical modeling, as well as their comparison. The results presented in this article are a part of the dissertation research «New technological solutions development for the bridge floor surface at transport interchanges» Kostenko S.А.

Impact of a tunnel on the TL of a vehicle floor in bare and trimmed conditions and investigation on the most suitable simplified geometry able to better represent such impact

NVH engineers are faced with the challenge of designing trim parts for vehicle interior and exterior, like inner dash insulators, carpets, underbody shields or engine encapsulations, which can be made with very different Bills of Materials (BOMs) including among others foams, felts or heavier layers. The measurables commonly used to rank various solutions are Transmission Loss (TL) and absorption. Depending on the numerical analysis method, different approaches may be considered for the evaluation of the TL of an automotive component. In particular, in Statistical Energy Analysis (SEA), automotive components are modeled as an assembly of panels having a simple shape, e.g. flat panels and/or panels with single or double curvature. Furthermore, in SEA the trim is normally modeled by means of the Transfer Matrix Method (TMM), which is essentially a 2-dimensional methodology. This paper intends to analyze in some depth the level of approximation that these practices bring with themselves, specifically in relation to the modelling of an automotive floor. More in detail, the aim of the paper is first to investigate what impact has the presence of the tunnel on the TL of a vehicle floor in bare and trimmed conditions and then to evaluate if the presence of the tunnel can be better modeled by using a semi-cylinder or three flat plates welded together in a trapezoidal shape, both shapes considered as a reasonable simplification of the actual geometry of a typical tunnel. The analysis is carried out at simulation level using FE. To investigate both air bone noise and structure borne noise transmission, two types of excitations are used: a diffuse acoustic pressure field applied to the entire floor surface and an imposed displacement applied to the edge of the floor surface. Furthermore, 3 different kind of trims are taken into consideration in order to analyze if and how the tunnel modeling strategy may influence the evaluation of the trim effectiveness.

How Can Floor Covering Influence Buildings’ Demand Flexibility?

Although the thermal mass of floors in buildings has been demonstrated to help shift cooling load, there is still a lack of information about how floor covering can influence the floor’s load shifting capability and buildings’ demand flexibility. To fill this gap, we estimated demand flexibility based on the daily peak cooling load reduction for different floor configurations and regions, using EnergyPlus simulations. As a demand response strategy, we used precooling and global temperature adjustment. The result demonstrated an adverse impact of floor covering on the building’s demand flexibility. Specifically, under the same demand response strategy, the daily peak cooling load reductions were up to 20–34% for a concrete floor whereas they were only 17–29% for a carpet-covered concrete floor. This is because floor covering hinders convective coupling between the concrete floor surface and the zone air and reduces radiative heat transfer between the concrete floor surface and the surrounding environment. In hot climates such as Phoenix, floor covering almost negated the concrete floor’s load shifting capability and yielded low demand flexibility as a wood floor, representing low thermal mass. Sensitivity analyses showed that floor covering’s effects can be more profound with a larger carpet-covered area, a greater temperature adjustment depth, or a higher radiant heat gain. With this effect ignored for a given building, its demand flexibility would be overestimated, which could prevent grid operators from obtaining sufficient demand flexibility to maintain a grid. Our findings also imply that for more efficient grid-interactive buildings, a traditional standard for floor design could be modified with increasing renewable penetration.

Analysis of Polish norms on thermal resistance and thermal comfort for underfloor heating

In the paper, there is an analysis of the requirements for the thermal resistance of floors with underfloor heating. It corresponds to the human physiology as much as possible, creates comfortable conditions at a lower temperature of the internal air, reduces the rise of dust by reducing convective flows, allows the use of low-grade heat carriers, especially from secondary and renewable energy resources, does not take up space in the room, minimally affects the interior. However, the temperature of the heating elements is significantly higher than the room temperature. At the same time, the requirements for thermal insulation under the heating elements should be higher than for structures without heating. As the analysis of the regulations in force in Poland has shown, this is not always observed. In many cases, the heat transfer resistance is lower by 42-181 %. The percentage difference in requirements for flooers over aisles in rooms with an air temperature of 16 °C and above is 160%. It will reach 215 %, according to the requirements that will be applied from 2021. In the case of floors over unheated rooms, the percentage difference between the requirements reaches 181 %. By the new norms in 2021, this difference will reach 215 %. Also, the normative limitation on the temperature of the floor surface does not always allow providing the normative level of comfort. In rooms of categories A and B, the surface temperature of the floor must be 20-28 °C. In the case of category C it should not exceed 30 °C. The most favorable conditions are achieved when the floor surface temperature is close to 23.5 °C. PN-EN 1264-4 standard allows the temperature of the floor surface in some rooms up to 33...35 °C. Thus, to ensure energy efficiency and comfort, it is necessary to harmonize the regulations with each other.

An analytical method to estimate temperature distribution of typical radiant floor cooling systems with internal heat radiation

Radiant floor cooling systems are increasingly used in practice. The temperature distribution on the floor surface and inside the floor structure, especially the minimum and average temperature of floor surface, determines the thermal performance of radiant floor systems. A good temperature distribution of the floor structure is very important to prevent occupant discomfort and avoid possible condensation in summer cooling. In this study, based on the heat transfer model of the single-layer homogeneous floor structure when there is no internal heat radiation in the room, this paper proposes a heat transfer model of single-layer floor radiant cooling systems when the room has internal heat radiation. Using separation variable methods, an analytical solution was developed to estimate temperature distribution of typical radiant floor cooling systems with internal heat radiation, which can be used to calculate the minimum temperature and the average temperature of typical composite floor structure. The analytical solution was validated by experiments. The values of the measured experiments are in a good agreement with the calculations. The absolute error between the calculated and the measured floor surface temperatures was within 0.45°C. The maximum relative error was within 2.31%. Prove that this model can be accepted. The proposed method can be utilized to calculate the cooling capacity of a typical multi-layer composite floor and will be developed in the future study for design of a typical radiant floor cooling system.

Natural research of the thermal process on the surface of irradiation by infrared heater

Comfortable conditions for people to stay in the production room with the use of infrared emitters depend on the uniform distribution of temperatures over the entire area of the irradiation zone. Therefore, the purpose of the research was to determine experimentally the temperature on the irradiation surface with an infrared heater and to summarize the results, for their further use in the design of infrared heaters in various production facilities. The distribution of temperatures on the irradiation surface was determined by the method of experimental studies. To derive the patterns of temperature field distribution on the irradiation surface, the experiment was carried out at variable power of the infrared heater Qheat, W, the height of its installation H, m and different blackness degrees of the floor surface εfloor, which depends on the floor material. The graphical distribution can prove the regularity of that heat in solid materials is distributed due to thermal conductivity – from particles with higher temperatures to less heated. Using mathematical methods of experimental data processing, experimental dependences were approximated to determine the relative temperature of the irradiation surface. The temperature gradient obtained graphically is directed along the normal to the isothermal surface in the direction of increasing temperature. This approach enables considering the development of process in the dynamics and allows the visualization of heating to adjust the basic parameters of process. Scientific results obtained in this work will allow developing a new methodological approach to the study of heating processes on the surface of irradiation by an infrared heater on the basis of a combination of physical and mathematical modeling, which can form an instrumental basis for the target study of such processes of formation of the thermal regime in production facilities. The thermal power of the infrared heater Qheat, W had the greatest influence on the value of the relative temperature of the floor surface tfloor. With constant values of the height of the heater, the blackness degree of the irradiation surface and with increasing the thermal power of the heater twice the value of the relative temperature of the irradiation surface increased by 9.7 %.

Numerical simulation and study of thermal characteristics of a lightweight floor heating system

The use of underfloor heating systems is an effective way to achieve thermal comfort for users in energy-efficient buildings. There are two kinds of such systems: traditional and dry-assembled. The first type is researched more deeply than the second one. The paper presents theoretical studies of the thermotechnical parameters of a water underfloor dry-assembled heating system. The design of the underfloor dry-assembled heating system, considered in the work, consists of a heat insulation (expanded polystyrene), on which the pipes of the heating system are located, in contact with an aluminum heat distribution plate. The system is covered with floor finishing. The calculation for a stationary operating mode of the floor heating system was carried out on the basis of a system of equations for momentum and energy. The model was validated using the results of experimental studies. The calculation results cause some overestimation of the experimental data, possibly, beecause of deviations in thermotechnical characteristics of materials. But the simulation model correctly estimates the behaviour of the system at change of its parameters. The paper concludes that this configuration of the underfloor heating system can be used in heating systems for residential and non-residential premises. The aluminum heat distribution plate significantly affects the heat transfer processes in the system. Due to the plate, the heat flux is made uniform in the plane of the floor surface, which has a positive effect on heat distribution and reduces thermal tension in the finish coating. The use of ceramic tiles increases the overall heat exchange efficiency of the system with the room air. An increase in the thickness of the expanded polystyrene board increases the value of the heat flux from the surface of the heated floor. An increase in the flow rate and temperature of the heat carrier also cause an increase in the density of heat flux from the floor surface.

Electricity Generation Using Spring-Powered Floor Pad

Walking is the most common activity in our daily life. When we walk, we lose energy to the floor surface. Vibration is one form of energy that is transferred from our weight on to the floor surface during every step. This energy can be harvested and converted into electrical energy. This research addressed the design and construction of a power generating floor pad which can be used to harvest electricity from human footsteps. The electric generating floor pad features springs mounted on its four corners. When somebody walks though the surface of the floor pad, the springs will be compressed because of the weight of the person causing it to dip down slightly. The shaft of the permanent magnet generator will rotate then rotate, thus voltage is generated. The generator can be connected to a battery so as to store electrical energy. Test performed on the device indicates that it is capable of converting human footsteps to a useful electrical energy to power small electrical devices. The magnitude of the generated voltage can be maximized by applying more force on the floor pad. The discharging time of the battery is longer when there are more footsteps applied to the floor pad. The device can be conveniently installed in the doorways of buildings or other heavy traffic areas. Through this research project, a new option for harnessing green electricity by footsteps is made available focusing on the use of springs and permanent magnet generators.

Design of Vernis Sprayer Using Macroergonomic Analysis and Design

The process of spraying varnish is an important part of this industry but it still uses minimal tools so that this process has several obstacles, namely wasted time, unreliable work positions, frequent defects, and disturbed other work stations. To overcome this, a varnish sprayer has been designed, but there are still many things that need to be improved in terms of shape. The research was conducted at SMEs AAT RATTAN CHANDY CRAFT which is engaged in rattan handicrafts such as chairs, tables, serving covers. From the data obtained, 21 out of 28 people experienced complaints in the arms and hands due to less ergonomic work positions and tools. This study uses the Macroergonomic Analysis and Design method, in order to obtain a varnish spray design proposal in the form of a rectangular, faceted iron frame, the main drive of the dynamo (motor), the belt rope as a power connector, the conveyor as a spraying route, the spray gun as a sprayer. The dimensions of this varnish sprayer are 230 cm high, 200 cm wide and 500 cm long. In the proposed working method, there must be two operators, the first operator at the input door of the lifting tool and putting the product on the conveyor, the second operator receiving at the output door of the tool. This eliminates bending and squatting activities because the conveyor height is made as high as 137 cm from the floor surface.