scholarly journals DETERMINATION OF HEAT TRANSFER RESISTANCE IN NON-STATIONARY THERMAL CONDITIONS

2020 ◽  
Vol 22 (6) ◽  
pp. 83-93
Author(s):  
A. N. Belous ◽  
G. A. Kotov ◽  
D. A. Sapronov ◽  
B. A. Novikov
Keyword(s):  
Heat Transfer ◽  
Real Estate ◽  
Thermal Characteristics ◽  
Thermal Conditions ◽  
Full Scale ◽  
Transfer Resistance ◽  
Advantages And Disadvantages ◽  
Fundamental Research ◽  
Cis Countries ◽  
Resistance To Heat

One of the main normalized heat engineering indicators of enclosing structures is the resistance to heat transfer. On the territory of the CIS countries there are a huge number of real estate objects designed and built in accordance with outdated standards for the consumption of heat energy for heating and ventilation, requirements for the heat-protective shell of buildings, which leads to energy overspending. All real estate objects put into operation before the tightening of the above-mentioned standards require determining the actual thermal characteristics of the enclosing structures and bringing them into compliance with the current legislation. The article analyzes existing methods for determining the heat transfer resistance of enclosing structures in full-scale conditions, and identifies the advantages and disadvantages of these methods. Based on the fundamental research of construction Thermophysics, a mathematical model for determining the resistance to heat transfer in full-scale conditions is proposed, taking into account the shortcomings of existing methods.

scholarly journals Proposals for standardization the heat transfer resistance of insulated walls of residential buildings in the Republic of Belarus

Vestnik MGSU ◽  
2021 ◽  
pp. 828-837
Author(s):  
Vyacheslav N. Chernoivan ◽  
Anna V. Torkhova ◽  
Nikolay V. Chernoivan ◽  
Vladimir G. Novoseltsev
Keyword(s):  
Heat Transfer ◽  
Residential Buildings ◽  
Outdoor Air ◽  
Heating Season ◽  
Main Criterion ◽  
Transfer Resistance ◽  
Air Temperatures ◽  
Urgent Task ◽  
The Republic ◽  
Resistance To Heat

Introduction. Resistance to heat transfer is considered the main criterion of energy operational efficiency in the design of enclosing structures of buildings and structures. Therefore, the calculation of the values of the normalized resistance to heat transfer, for each locality of the Republic of Belarus, taking into account the actual outdoor temperatures and the duration of the heating season is an urgent task. Materials and methods. To assess the energy efficiency of enclosing structures, the value of annual heat losses Q, kWh/m2, through 1 m2 of the structure was adopted. The calculation of the values of the normalized heat transfer resistance for each locality of the Republic of Belarus, taking into account the actual outdoor air temperatures and the duration of the heating season, was carried out according to the method recommended by V.G. Gagarin. A comparative analysis of the results obtained according to the methods recommended by TCP 45-2.04-196-2010* and SP 50.13330.2012 is carried out. Results. The calculations determine the values of the normalized heat transfer resistance for each locality of the Republic of Belarus, taking into account the actual outdoor air temperatures during the heating period and the duration of the heating season. To facilitate the design of insulated walls, a map of the recommended (calculated) values of the heat transfer resistance of the external walls of residential buildings for the territory of the Republic of Belarus is constructed. Conclusions. According to the results of the performed studies, it was found that the economic efficiency in the design of insulated walls according to the method recommended by TCP 45-2.04-196-2010*, depending on the region of the Republic of Belarus for which the design is being carried out, is on average from 6 to 8 BYN per 1 m2 of insulated wall.

scholarly journals OPTIMIZATION OF HEAT PROTECTION CHARACTERISTICS OF COUNTRY COTTAGE ENCLOSURES

2021 ◽  
Vol 11 (1) ◽  
pp. 39-45
Author(s):  
Yuri S. VYTCHIKOV ◽  
Mikhail E. SAPAREV ◽  
Vladislav A. GOLIKOV ◽  
Evgeniy G. SAFRONOV
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Thermal Protection ◽  
Minimum Energy ◽  
Thermal Conditions ◽  
Outer Wall ◽  
Wall Material ◽  
Transfer Resistance ◽  
Heating Systems ◽  
Minimum Energy Consumption

The article presents a method for determining the minimum permissible value of the heat transfer resistance of the outer wall, at which the minimum energy consumption is achieved during the operation of buildings with variable thermal conditions. A review of the sources devoted to this problem showed the presence of high costs of thermal energy during the heating of premises. On the basis of studies of all components of energy consumption in the operation of premises with intermitt ent heating systems, the authors of the article propose a method for determining the minimum permissible resistance to heat transfer, which provides minimum energy consumption. According to the described method, the calculation was made for external walls made of various materials. The analysis of the obtained results showed that a signifi cant infl uence on the minimum permissible value of the heat transfer resistance is exerted by a complex of thermophysical values cρλ. The presented graphical dependence R0 усл on the complex cρλ allows the designer to rationally choose a wall material that provides a minimum of energy consumption during the operation of the building. In the context of rising energy tariff s, such optimization of thermal protection characteristics is especially important for country cott ages operated in intermitt ent heating conditions.

scholarly journals Thermal characteristics of yttria stabilized zirconia nanolubricants

2012 ◽  
Vol 16 (2) ◽  
pp. 481-487 ◽  
Author(s):  
Ganapathy Sakthinathan ◽  
Raju Saravanan ◽  
Chandrasekaran Uthirapathy
Keyword(s):  
Heat Transfer ◽  
Electron Microscope ◽  
Viscosity Index ◽  
Thermal Characteristics ◽  
Thermal Conditions ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Automotive Engine ◽  
Heat Stable ◽  
Zirconia Nanoparticles

The transition from microparticles to nanoparticles can lead to a number of changes in its properties. The objective of this work is to analyze the thermal, tribological properties of yttria stabilized zirconia nanoparticles. Nanosized yttria stabilized zir conia particles were prepared by milling the yttria stabilized zirconia (10 ftm) in a planetary ball mill equipped with vials using tungsten carbide balls. After 40 hours milled the yttria stabilized zirconia nanoparticles of sizes ranging from 70-90 nm were obtained. The phase composition and morphologies of the assynthesized particles were characterized by energy dispersive X-ray analysis, scanning electron microscope, transmission electron microscope, thermogravimetric analysis and differential scanning calorimeter, and the images of the same were obtained. From TG-DSC analysis it was confirmed that, the yttria stabilized zirconia nanoparticles were heat stable under different thermal conditions which is due to the addition of yttria to pure zirconia. Due to this property of yttria stabilized zirconia nanoparticles, it can be widely used in high transfer application such as lubricant additives. The heat transfer properties of automotive engine lubricants were determined by utilization of measured thermal conductivity, viscosity index, density, flash point, fire point and pour point revealed that lubricants with additive constituents have a significant effect on the resultant heat transfer characteristics of the lubricants.

OPTIMIZATION OF HEAT-SHIELDING CHARACTERISTICS OF THE EXTERIOR WALLS OF COUNTRY COTTAGES, INSULATED WITH MONOLITHIC FOAM CONCRETE

2018 ◽  
Vol 8 (3) ◽  
pp. 22-25
Author(s):  
Yury S. VYTCHIKOV ◽  
Mikhail Ye. SAPAREV ◽  
Vladislav A. GOLIKOV
Keyword(s):  
Heat Transfer ◽  
Outer Wall ◽  
Heating Time ◽  
Exterior Wall ◽  
Foam Concrete ◽  
Transfer Resistance ◽  
Warm Up ◽  
Shielding Properties ◽  
Heat Shielding ◽  
Resistance To Heat

The heat-shielding properties of three-layer external walls insulated with monolithic foam concrete are considered in the article. The temperature is given in rooms operated in intermitt ent heating conditions. An optimal exterior wall design is proposed using monolithic foam concrete for the construction of country cott ages. For this design, the results of heat engineering calculations are presented using the analytical dependence of determining the heat transfer resistance, which ensures the minimum warm-up time of the wall. The results of the calculation are presented in tabular form for a given heating time and density of foam concrete. Also a relationship is described to determine the maximum allowable resistance to heat transfer of the outer wall at diff erent densities of monolithic foam concrete.

scholarly journals USE OF MONOLITHIC FOAM CONCRETE IN ENCLOSING STRUCTURES OF BUILDINGS AND STRUCTURES WITH VARIABLE THERMAL CONDITIONS

2018 ◽  
Vol 8 (4) ◽  
pp. 10-14 ◽  
Author(s):  
Yury S. VYTCHIKOV ◽  
Mikhail Ye. SAPAREV ◽  
Vladislav A. GOLIKOV
Keyword(s):  
Heat Transfer ◽  
Thermal Conditions ◽  
Outer Wall ◽  
Engineering Calculation ◽  
Heating Time ◽  
Thermal Engineering ◽  
Foam Concrete ◽  
Insulating Layer ◽  
Optimum Range ◽  
Resistance To Heat

This article considers the features of the use of monolithic foam concrete as a heat-insulating layer in the building enveloping structures of buildings operated under intermitt ent heating conditions. To assess the eff ectiveness of the use of monolithic foam concrete in building enveloping structures, a thermal engineering calculation of the outer wall, insulated with the use of monolithic foam concrete, was carried out. Based on the calculations carried out by the authors, graphs of the dependence of the heating time of multilayered enclosing structures on the thickness of the heat-insulating layer and the reduced resistance to heat transfer of the structure were obtained. The optimum range of thicknesses and densities of monolithic foam concrete for thermal insulation of external walls of buildings, operated in conditions of intermitt ent heating, is off ered. This calculation also showed that the use of foam concrete as a heater from the inside of the outer wall can reduce the load on the foundation of the building.

Jones Enterprises Real Estate Investment Trust: Comparing U.S. and Canadian Acquisition Accounting, Balance Sheet and Security Commission Reporting, and Initial Public Offering Location

2018 ◽  
Vol 33 (2) ◽  
pp. 35-42
Author(s):  
Natalie Tatiana Churyk ◽  
Alan Reinstein ◽  
Lance Smith
Keyword(s):  
Real Estate ◽  
Initial Public Offering ◽  
Financial Reporting ◽  
Balance Sheet ◽  
Accounting Students ◽  
Real Estate Investment ◽  
Generally Accepted Accounting Principles ◽  
Balance Sheets ◽  
Advantages And Disadvantages ◽  
Public Offering

ABSTRACT Based on a Big 4 real estate audit partner's client, this case introduces graduate research and advanced financial accounting students to acquisition accounting under U.S. generally accepted accounting principles (GAAP) and International Financial Reporting Standards (IFRS), provides a perspective on real estate investment trusts (REITs), and requires analyzing a U.S. versus Canadian (Ontario) initial public offering (IPO). Students list U.S. and Canadian advantages and disadvantages of REITs, record a portfolio purchase, prepare U.S. GAAP and IFRS balance sheets in order to grasp major REIT reporting differences, contrast the key provisions between U.S. and Canadian (Ontario) securities commissions' IPO reporting, and consider ongoing securities commissions' reporting options. Finally, students will recommend whether the IPO should be issued in the U.S. or Canada. Completing the case helps students: (1) grasp U.S. GAAP and IFRS acquisition accounting methods and different REIT presentations; and (2) recognize that the country selected for the IPO depends upon the issuer's circumstances and preferences.

Experimental Study on Thermal Characteristics of Finned Coil LHSU Using Paraffin as Phase Change Material

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Guansheng Chen ◽  
Nanshuo Li ◽  
Huanhuan Xiang ◽  
Fan Li
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Phase Change ◽  
Phase Change Material ◽  
Water Flow ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Heat Transfer Fluid ◽  
Latent Heat Storage ◽  
Change Material

It is well known that attaching fins on the tubes surfaces can enhance the heat transfer into and out from the phase change materials (PCMs). This paper presents the results of an experimental study on the thermal characteristics of finned coil latent heat storage unit (LHSU) using paraffin as the phase change material (PCM). The paraffin LHSU is a rectangular cube consists of continuous horizontal multibended tubes attached vertical fins at the pitches of 2.5, 5.0, and 7.5 mm that creates the heat transfer surface. The shell side along with the space around the tubes and fins is filled with the material RT54 allocated to store energy of water, which flows inside the tubes as heat transfer fluid (HTF). The measurement is carried out under four different water flow rates: 1.01, 1.30, 1.50, and 1.70 L/min in the charging and discharging process, respectively. The temperature of paraffin and water, charging and discharging wattage, and heat transfer coefficient are plotted in relation to the working time and water flow rate.

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