Papers by Keyword: Energy Conservation

Abstract: In this study, low-thermal emissivity coatings were developed using aluminum leafing particles dispersed in an acrylic binder. The aluminum particles were modified through a ball milling process to enhance their leafing properties, with milling times ranging from 5 to 15 h. The effects of milling time on particle size, morphology, and leafing degree were examined using scanning electron microscopy (SEM) and laser diffraction analysis. Coatings with different particle volume concentrations (PVC) and thickener contents were prepared, and their thermal emissivity was evaluated. Results showed that milling time significantly affected the leafing behavior of the aluminum particles, with longer milling times leading to improved dispersion and lower emissivity values. The addition of a thickener enhanced particle distribution, but excessive concentrations resulted in void formation due to hindered solvent evaporation. The lowest thermal emissivity was achieved at a milling time of 15 hours and 10% PVC, providing valuable insights for the design of effective low-emissivity coatings for thermal management applications.

Abstract: The paper presents an experimental study on the production of non-fired ceramic tiles from rice husk ash (RHA) and green glass cullet (GGC) composites as a novel eco-friendly material. Eighteen mixture formulations were constructed as compared to control formula, specimens were uniaxially pressed at 10 MPa and then cured at room temperature for 7 and 28 days. Non-fired tiles (formula A4, B11, and C17) containing 20% GGC were mixed with 0%, 5%, and 10% RHA. The modulus of rupture can be increased by 87.23%, 48.8%, and 19.4%, respectively, at 28 days of curing as compared to control formula. These results were also coherent with microstructure characterization by scanning electron microscopy (SEM). Furthermore, formula A4 and C17 were selected to compare energy costs with wall tiles fired at 950^°C. They were the same amount of energy-saving costs by 5.19 USD/m². From these results, the new eco-friendly products can produce with a combination of RHA and GGC wastes which can enhance the physical properties due to the pozzolanic reaction. Moreover, the proposed non-fired ceramic tiles can conserve energy and reduce manufacturing costs.

Abstract: Energy saving in buildings is largely determined by the energy efficiency of the external building envelopes. The latter, as a rule, are the multilayer and incorporate structural and heat-insulating layers. The presence of individual hygroscopic salts and their mixtures in building materials changes their physical and chemical properties. Due to the increase in the sorption properties of building materials and changes in the inter-pore substance composition, humidity increases and the heat-protective properties decrease. This paper presents the results of the experimental and theoretical studies on the salts’ effect assessment on the change in moisture content and thermal conductivity of building materials due to the salt solutions and crystals’ presence in the pore space. To study the saline building materials’ thermal conductivity, the mathematical modeling methods using the theory of flow and bringing the materials’ structure to a unit cell are used. It is shown that the change in thermal conductivity occurs due to the crystalline salt precipitation from the solutions in the material’s pores, to the changes in their initial chemical properties, to the changes in the properties of the vapor-air mixture above the salt solutions due to diffusion. The results obtained make it possible to establish the hygroscopic salts’ influence significance in solid and liquid phases on the building materials’ thermal conductivity. A scheme for determining the thermal conductivity of building materials is proposed, taking into account salt effects, including the determination of: the components’ volume concentrations; sequentially the thermal conductivity of the material’s shell; salt crystals, a solid phase consisting of the material’s shell and crystalline salt, a binary and multicomponent saline solution, the pore space and the pore substance inside. The general formula for determining the thermal conductivity of a saline building material is given.

Abstract: The use of performance, application status and existing problems of organic and inorganic thermal insulation materials, which are commonly used in the external walls of the building, are described in detail in this paper. Organic thermal insulation materials with low thermal conductivity, good thermal insulation performance, but with the flammable, low fire rating, poor safety, then it needing for flame retardant treatment. However, Inorganic thermal insulation materials with flame retardant, high fire rating, good safety performance, but poor thermal insulation properties than the organic insulation materials, so it needs to develop a low thermal conductivity of inorganic insulation materials.In the end, we pointed out that the inorganic insulation materials with low thermal conductivity and excellent comprehensive properties are expected to be the first choice for building thermal insulation materials.

Abstract: Reducing fuel consumption and ensure occupants thermal comfort are two important considerations when designing a vehicle air conditioning system. By using direct current electric compressor, speed of compressor can be controlled by changing the frequency of the inverter. Fuzzy logic controller (FLC) was developed to imitate the performance of human expert operators by encoding their knowledge in the form of linguistic rules. The system is installed to a 5-door compact car with 1.2cc four-cylinder engine with data acquisition system to monitor the temperature of the cabin, coefficient of performance (COP) and fuel consumption. Temperature set-point of 22°C with original belt-driven, on/off and FLC electric direct current compressor at one hour experimental periods. The experimental results indicate that the FLC can save more fuel compared to on/off controller and belt-driven compressor.

Abstract: The present scenario of energy conservation has witnessed many innovative and eco-friendly techniques and one such area where there is a necessity to conserve energy is foundries. Foundries also pollute the atmosphere with greenhouse gases contributing to 296143037.6 metric tons annually. The proposed technique in this paper aims at reducing the energy utilized in melting the scrap material at foundries by solar thermal energy. In the methodology proposed, solar energy is concentrated onto the scrap placed on a receiving platform using a parabolic trough and heats it up so that the heated scrap takes lesser energy to melt. The experiments resulted in preheating temperature of 100 °C when placed on a receiving platform and 110°C when copper shots are used to conduct heat from receiver to the scrap. This translates to energy conservation of 6%. This eco-friendly technique when adopted can result in substantial savings in consumption and environmental protection.

Abstract: In conventional casting, the riser is separated from the casting and remelted for further use. If the riser can be configured to house a product, it can save energy for separately melting in making that product. In present work the separated riser is used as a raw material for another product without subjecting it to melting. A green sand mould consisting of a cubical pattern and LM 4 grade aluminium metal were used for the experiment. The riser used was designed to embody a cylindrical rod of 3.5 cm diameter. For the product given out by the riser used in this research energy saving to the tune of 23.5 % could be achieved. If this is extended to annual production of 98,593,122 tons of castings in the world, the cumulative energy savings amount to 17840 GWh, minimizing 7671200000 tons of CO₂ per year. Hence such innovations can be explored more deeply for industrial implementation.

Abstract: Energy conservation is a major topic of concern since our energy sources are exhausting exponentially. This paper focuses on waste heat recovery using which scrap preheating is done in metal castings using sand molds. During solidification of molten metal, most of the heat is lost to the sand. The proposal is to prepare the sand mould with aluminium shots surrounding the mold cavity. These shots absorb some of the heat from the solidifying metal in the mold cavity. The heated shots are separated from the mold and they are allowed to transfer their heat energy to the metal scrap by conduction. The experiments indicate that at least 6.4% of heat recovery is achievable. This will be instrumental in reducing the enormous amount of energy spent to melt the metal considering the fact that casting is the most widely used manufacturing process globally.

Abstract: This paper presents a recent swarm intelligence technique viz. Cuckoo Search Algorithm (CSA) for solving the Optimal Chiller Loading (OCL) problem for energy conservation. Multi-chillers system has been widely used by commercial and industrial facilities to provide cooling energy. The main problem of multi-chillers system is that it conserved huge amount of energy. In this study, Partial Load Ratio (PLR) of the chiller is used as the variables to be optimized while the power consumption in kW is selected as the objective function to be minimized. On the other hand, CSA is a one of well-known swarm intelligence techniques that has been used to solve many optimization problems. In order to show the effectiveness of CSA in solving OCL problem, a case study with six-chiller system is considered. Results obtained are compared with other techniques available in literatures.

Abstract: In the context of Russian power and transport modernization the problem of new ways searching of energy efficiency increasing based on area has been assuming significance and topicality within last years. The goal of authors’ research is the identification of current problems in the power engineering and transport sectors under modern economic conditions and the development of municipal education tendencies (directions) from the social and energy efficiency prospective. The number of state investment projects have been developed and justified from the economic and energy efficiency point of view. The proposed and justified directions and measures (actions) related to the implementation of state energy efficiency project on the area-based development will be helpful to State Government bodies. The research was carried out at the support of the program for strategic development of Novosibirsk State Technical University, project No C-31.