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The Evolution of Natural Gas Prices in EU Countries and their Impact on the Country’s Macroeconomic Indicators

Liptáková Erika, Rimár Miroslav, Kizek Ján, Šefčiková Zuzana

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 2

255--273

EN

In the article, the authors characterize the current European market with natural gas, describing differences in prices for households and prices for companies from the point of view of individual components, where they focus more on taxes, levies and fees. The article further deals with the possible impact of the price of natural gas on the country's economy, more specifically, the correlation with inflation, unemployment and interest rates. The main aim of the authors is to establish an appropriate econometric model, which describes the impact of the price of natural gas together with the unemployment rate and interest rates on the inflation of the country. The price of natural gas, of this strategic raw material, is one of the factors that can influence the processes for low-carbon technologies or more precisely, the process of EU decarbonisation and with it the associated amount of CO2 emissions.

2

Natural gas saving and emissions decrease in public health care sector – a case study

Mierka Otto, Variny Miroslav, Skalíková Ingrida, Sámel Peter, Kizek Ján, Súth Róbert, Nagy Karol

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 1

119--127

EN

A study on natural gas saving and emissions decrease in the public health care sector is presented. The analyzed hospital complex belongs to the largest ones in Slovakia and uses both hot water and water steam for heating purposes. Visual steam system inspection revealed serious inefficiencies, including steam venting, missing pipelines insulation and obsolete steam sources with dysfunctional blow-down system. Defined experiment with stepwise steam appliances shutdown enabled quantification of excess natural gas consumption due to these inefficiencies. Measures proposed for the solution of this state are inexpensive, with a short payback period. The expected natural gas savings amount up to 3200 MWh/year, which represents roughly 50% of the total natural gas consumption in the hospital complex.

PL

Niniejszy artykuł prezentuje studium przypadku na temat ograniczenia zużycia gazu ziemnego i emisji w sektorze zdrowia publicznego. Analizowany kompleks szpitalny należy do największych na Słowacji i używa do ogrzewania zarówno ciepłej wody użytkowej, jak i pary wodnej. Kompleks ten będzie w najbliższych latach poddany renowacji, włącznie z instalacją dystrybucji mediów. Analiza obecnego systemu i wynikające z niej zaproponowane sposoby na zaoszczędzenie energii oferują redukcję kosztów powiązanych z przyszłą inwestycją. Wizualna ocena systemu dystrybucji pary wodnej ujawniła poważne wady tego systemu, w tym w odpowietrzaniu systemu, uszkodzonej bądź brakującej izolacji rur, przestarzałych bojlerach parowych z niedziałającym systemem usuwania zanieczyszczeń. Eksperyment ze stopniowym wyłączaniem urządzeń parowych umożliwił ilościowe określenie nadmiaru zużycia gazu ziemnego spowodowanego wspomnianymi niedostatkami. Metodologia takiego eksperymentu jest uniwersalna i łatwa w zastosowaniu w jakimkolwiek innym budynku użyteczności publicznej gdzie podobny system pary wodnej jest w użyciu. Zaproponowane rozwiązania dla poprawy takiego stanu są niedrogie i z krótkim czasem zwrotu inwestycji. Zastosowanie nowej izolacji rur, naprawa odwadniaczy oraz naprawa zaworów redukcyjno-regulacyjnych do odpowietrzania pary w odpowietrznikach są przedmiotem rozważań. Oczekiwana redukcja zużycia gazu ziemnego wynosi do 3200 MWh/rok, co stanowi około 50% rocznego zapotrzebowania tego gazu w kompleksie szpitalnym. Ocena środowiskowa zaproponowanych zmian pozwala oczekiwać redukcji emisji dwutlenku węgla na poziomie 644 ton rocznie oraz tlenków azotu na poziomie 0.75 ton rocznie.

3

Defining the mathematical dependencies of NOx and CO emission generation after biomass combustion in low-power boiler

Lukáč Ladislav, Kizek Ján, Jablonský Gustáv, Karakash Yevgeniy

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 3

153--163

EN

The paper deals with the study of the influence of various factors, which have an impact on emissions such as NOx, CO, which have been verified by measurements. Biomass in the form of wood chips as fuel of different moisture content from 9% to 25% has been tested at various boiler outputs. The presented work also defines the mathematical dependencies of NOx and CO emission generation by using regression analysis from measured data after biomass combustion in low-power boilers. The paper also describes a mathematical model of biomass combustion. The mathematical model was created to verify the measured data and prediction of emission generation in the process of biomass combustion. This model consists of combustion of stoichiometry, calculation of combustion temperatures, obtained regression equations of NOx and CO. At the end of this paper, the obtained results are compared with the calculated models as well as the results of the defined dependencies from the regression analysis.

4

Adsorptive solar refrigerators based on composite adsorbents 'silica gel – sodium sulphate'

Belyanovskaya Elena A., Pustovoy Grigoriy N., Sukhyy Kostyntyn M., Sergiyenko Yana O., Yeromin Oleksandr O., Prokopenko Elena ., Gubinsky Mikhailo V., Kizek Ján, Lukáč Ladislav

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 3

200--208

EN

The operation processes of adsorptive solar refrigerators based on composite adsorbents ‘silica gel - sodium sulphate’ were studied. The correlation between the adsorbent composition and the coefficient of the energy performance of the device was stated. As a consequence of the decreasing of adsorbent mass, the coefficient of performance is increased when sodium sulphate content in the composite increased. Effect of the regeneration process parameters on the composite on the coefficient of performance of the adsorptive refrigenerator was stated. The growth of the coefficient of performance is shown to result from decreasing the difference between adsorbent temperature and regeneration temperature from 85 to 55°C. The maximum values of the coefficient of performance of studied solar adsorptive refrigenerator about of 1.14 are stated for composites containing about 20 wt. % silica gel and 80 wt. % sodium sulphate.