scholarly journals THE SIMPLEST MATHEMATICAL MODEL OF THE ENERGY EFFICIENCY OF LAYERED BUILDING ENVELOPES

2017 ◽  
Vol 254 (4) ◽  
pp. 28-33 ◽  
Author(s):  
D.D. Zaborova ◽  
M. I. Kukolev ◽  
M.T. Mussorina ◽  
M.R. Petritchenko
2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Fan Yang ◽  
Kotaro Tadano ◽  
Gangyan Li ◽  
Toshiharu Kagawa

Factories are increasingly reducing their air supply pressures in order to save energy. Hence, there is a growing demand for pneumatic booster valves to overcome the local pressure deficits in modern pneumatic systems. To further improve energy efficiency, a new type of booster valve with energy recovery (BVER) is proposed. The BVER principle is presented in detail, and a dimensionless mathematical model is established based on flow rate, gas state, and energy conservation. The mathematics model was transformed into a dimensionless model by accurately selecting the reference values. Subsequently the dimensionless characteristics of BVER were found. BVER energy efficiency is calculated based on air power. The boost ratio is found to be mainly affected by the operational parameters. Among the structural ones, the recovery/boost chamber area ratio and the sonic conductance of the chambers are the most influential. The boost ratio improves by 15%–25% compared to that of a booster valve without an energy recovery chamber. The efficiency increases by 5%–10% depending on the supply pressure. A mathematical model is validated by experiment, and this research provides a reference for booster valve optimisation and energy saving.


2012 ◽  
Vol 49 (6-I) ◽  
pp. 32-43 ◽  
Author(s):  
A. Ozolinsh ◽  
A. Jakovich

Abstract The heat and moisture transport in multi-layer walls is analysed for five building units. Using the developed program, a typical of Latvian conditions temperature and relative humidity profiles in multi-layered constructions has been obtained and the indoor heat losses estimated. Consideration is also given to the risk of condensate formation and to the influence of moisture on the U-value. The created mathematical model allows forecasting the energy efficiency and sustainability of different technical solutions as refer to the heat and moisture transport in buildings.


2015 ◽  
Vol 792 ◽  
pp. 370-374 ◽  
Author(s):  
Natalia Tatarinova ◽  
Dmitry Suvorov

The article proposes and being tested a methodology that allows using the mathematical model developed to clarify the possible impact of a precise process moisture measurement on the performance of energy efficiency of the cogeneration turbines.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 859
Author(s):  
Jadwiga Świrska-Perkowska ◽  
Andrzej Kucharczyk ◽  
Jerzy Wyrwał

A numerical model of a solar wall (SW) with transparent insulation (TI) is proposed in this article. The model is based on the finite-difference method and thermal conductivity equation, with a heat source term for the absorber. Using this model, the energy efficiency of a solar wall with transparent insulation (SW-TI) with honeycomb insulation made of modified cellulose acetate was analyzed in the case of different climatic conditions prevailing in Poland, different orientations of the envelope, and different insulation thicknesses. Simulations were carried out throughout the whole heating period. Monthly energy balances and temperature distributions for the analyzed envelopes at individual moments of the heating period are the basic results of the simulations. It was found that the use of 108 and 88 mm thick insulation was the most recommended in the considered temperate climate. Placing transparent insulation on a wall with an eastern or western orientation caused the annual heat balance of the envelope to decrease by 24–31% in relation to the value of this balance in the case of a southern orientation. The monthly heat balances obtained using the proposed model give results consistent with the method of calculating heat gains for opaque building envelopes with transparent insulation included in the PN-EN ISO 13790:2008 standard.


Author(s):  
Pawel Olszewski ◽  
Claus Borgnakke

The aim of this research is to estimate the influence of compressed air volumetric capacity on the energy consumption in systems equipped with oil-lubricated screw compressors. A mathematical model of oil-lubricated screw compressors has been proposed. The model is verified by comparing with real measurements, and overall uncertainty analysis is estimated. An in-house developed numerical code (c++) is used to calculate the energy consumption in 252,000 combinations. The final result can be used to estimate the energy efficiency of existing air systems and to assess potential energy savings due to changes in the operation of the system and its control strategy.


2020 ◽  
Vol 12 (4) ◽  
pp. 66-72 ◽  
Author(s):  
Aleksandr Ignatyuk ◽  
S. Nikolenko ◽  
Svetlana Sazonova

The paper analyzes and develops proposals to improve the energy efficiency of the building of MBOU «Lyceum No. 65» in Voronezh. The energy survey was carried out in order to comply with the requirements of Article 13 of Federal Law of November 23, 2010 No. 261-ФЗ «On Energy Saving and on Improving Energy Efficiency and on Amending Certain Legislative Acts of the Russian Federation». The survey was carried out using a Testo 881-2 thermal imager, a digital thermometer Testo 905-T2, a meter of heat flux density and ITP temperature - MG4.03 / 5 (I) «Potok».


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