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Archiv článků od 1.12.2022 do 11.12.2024

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Trubicové solární kolektory, foto © TZB-info
11.12.2024
Ing. Lukáš Skalík, PhD., EUR ING, Stavebná fakulta STU Bratislava

It is possible to design solar energy systems (SES) with solar collectors in several ways: manually - by calculation; using software - there are several calculation programs for SES design, e.g. T*Sol from the renowned German company Valentin software for the calculation of thermal heat collectors, or PV*Sol for the design and simulation of photovoltaic power plants of any size; or according to the manufacturer's instructions - if we know the manufacturer/supplier of the equipment when designing the SES, we can use the recommended calculation procedures from the design documents of the given company, provided that they are available.

17.11.2024
Ing. Jakub Vrána, Ph.D., Ústav TZB, Fakulta stavební VUT v Brně

The article discusses the history of sanitation installation, i.e. water installation, drainage systems inside buildings and gas installation pipework for buildings from the earliest times to 1948 and is primarily focused on the history of this field in the territory of the former Czechoslovakia. It also deals with the history of the plumbing trade, contemporary legal regulations, technical standards and professional literature on the territory of the former Czechoslovakia.

25.8.2024
Ing. Eliška Grmelová, prof. Ing. Jaromír Říha, CSc.

Current climate changes require adjustments in water management. One of the technical measures is the construction of reservoirs. Already in 1953, locations for future reservoir construction were designated under the State water management plan of the Czechoslovak Republic. Currently, these locations are recorded in the General Plan for Areas Protected for Surface Water Accumulation. Number of protected locations has changed over time, from the original 518 to the current 86. For a more detailed concept of water management and technical solutions have been selected six reservoirs from the Morava River Basin: Borovnice, Kuřimské Jestřabí, Vysočany, Brodce, Plaveč, and Bělkovice. The schemes will provide volume about 120 mil. m3 with total take-off up to 2.5 m3/s. They will ensure a minimum residual flow under the dam and enable the production of hydropower with a total output of 0.5 MW. The Bělkovice scheme was chosen to demonstrate the solution.

21.8.2024
Ing. Ondřej Zedník, doc. Ing. Michal Kriška, Ph.D.

Constructed treatment wetlands use a system of filter beds as the main treatment stage. Currently, the most used type of filter is the vertical flow bed, which is formed by layers of natural aggregates. The suitability of a material for use in the filter body is determined, among other things, by its hydraulic conductivity. For the main filtration layers of vertical filters, it is necessary to meet the required value of the saturated hydraulic conductivity coefficient located in the range of 10−4–10−3 m s−1. This article focuses on the determination of the hydraulic conductivity of recycled aggregates made from brick and concrete. The conductivity of raw materials is approximately 10−5 m s−1, but for materials treated by washing the saturated conductivity values are in the required range.

12.8.2024
doc. Ing. Tereza Pavlů, Ph.D., Ing. Jan Pešta

The contribution summarizes the fundamental chapters of the transported standard to re-demolition audit and building dismantling as a standard procedure for structure removal. The purpose of the standard will be to prescribe how the pre-demolition audit should proceed, what information it should contain, and how the deconstruction of the building should take place, in order to achieve the maximum possible utilization of the obtained materials. The motivation is primarily the return of quality raw materials to production and the reduction of primary resource extraction, which is one of the goals of sustainable development.

1.7.2024
prof. Ing. Leonard Hobst, CSc., Ing. Monika Doležalová, Ing. Pavel Klika, Ph.D.

The preserved detailed data on the consumption of fuel (coke) for heating and hot water preparation in functionalist apartment building from the 1930s led to the idea to compare the energy consumption of these buildings at the time of their construction with the present day and to observe how the modernization interventions in both the heating system and the actual construction of the building are manifested and to quantify these modernization interventions.

5.2.2024
Ing. Jiří Novotný, Univerzitní centrum energeticky efektivních budov, ČVUT v Praze

The design of a photovoltaic system taking into account heat loss, external and internal gains, the method of heating and water heating is made possible by a calculation tool created for the balancing of buildings with photovoltaic systems. In the example, combinations of FS with a heat pump or with an electric boiler are compared.

Foto © olegmalyshev, Fotolia.com
7.12.2023
Ing. Karel Plotěný, ASIO

The paper discusses solutions to rural sanitation. As population density decreases, the cost of central sanitation rises, and so villages with high sanitation costs risk having sewerage charges above the socially acceptable water price. This is also why other methods of sanitation should be used. In addition, in future, rural solutions should take into account not only the economic aspect but, as with other investments, all aspects of sustainability (see EGS assessment). Following the experience of climate change impacts, experience of natural phenomena and war events, the impact on climate change and the resilience of solutions to risks should also be part of the assessment.

Foto © Fotolia.com
18.10.2023
doc. RNDr. Dana Procházková, Ph.D., DrSc., ČVUT v Praze, Fakulta strojní

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The fourth part contains a conclusion, characteristics of new aspects addressed by the professional sphere for practice and a list of used literature.

Foto © fotovapl, Fotolia.com
17.10.2023
doc. RNDr. Dana Procházková, Ph.D., DrSc., ČVUT v Praze, Fakulta strojní

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The third part summarizes the findings on the checklist methodology and provides examples for pipelines.

Foto © Fotolia.com
13.10.2023
doc. RNDr. Dana Procházková, Ph.D., DrSc., ČVUT v Praze, Fakulta strojní

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The second part summarizes the knowledge and principles of risk management and lists the sources of risks for the pipeline.

Foto © Andrei Merkulov, Fotolia.com
11.10.2023
doc. RNDr. Dana Procházková, Ph.D., DrSc., ČVUT v Praze, Fakulta strojní

The presented set of four communications deals with the risk management in favour of safety applied to the operation of pipelines. It respects current professional knowledge and presents it in the concept promoted by the UN, the European Union, the OECD and others. The first part introduces terms used in engineering practice, which deals with risks and safety and introduces knowledge that is relevant to pipeline safety.

Foto © adragan, stock.adobe.com
13.9.2023
Ing. Ondřej Zedník, doc. Ing. Michal Kriška, Ph.D.

The agricultural holdings built in the 1970s have, from today's perspective, an inadequate wastewater management concept associated with the operation of single sewers. The paper deals with the solution of the conceptual approach presented on a specific agricultural site. Extensive technologies were used for wastewater treatment, represented by a model vertical filter with integrated aeration, which should show adequate results.

5.7.2023
Ing. Karolína Hudec Jakubíková

This paper deals with the study of the effect of the use of styrene in a polyester resin as a polymer binder in a trenchless rehabilitation composite. The different formulations also contain secondary raw materials as waste foam glass, basalt frit, waste glass from solar panels and fly ash. In the development of the formulations, which are subsequently used to saturate the polymer sleeves, the influence on the mechanical properties of the whole composite is mainly investigated. The mechanical parameters investigated include mainly the flexural modulus, the stress at first failure, the flexural deformation, adhesion of the lining to the pipe. The work found that the decrease in mechanical properties for the non-styrene variant is not so significant as to prevent its effective use in the composite.

16.1.2023
Ing. Viacheslav Shemelin, Ph.D., doc. Ing. Tomáš Matuška, Ph.D.

An analysis of a central and decentralized solar domestic hot water system for an apartment building shows that the usable solar gain and year-round efficiency are similar, but the solar coverage and the need for backup heat source energy are fundamentally different.

22.12.2022
RNDr. Martin Procházka, geologické dozory staveb, SG Geotechnika Praha

Recently, there have been more and more cases of suspected influence on water levels. There are more and more related disputes with this trend. However, the employees of water authorities have no choice but to rely on the experience of the geologist who prepared the project. In terms of form, the project can be processed well. But fatal problems can arise in terms of well operation. A special chapter is the wells for heat pumps with all their shortcomings and huge technical problems with grouting cement mixtures resulting from small diameters of wells. The aim of this paper is to inform about the wide possibilities of well logging to find out the real cause of the problems related to the level drops and to suggest the optimal way of remediation.

8.12.2022
Mgr. Jakub Mareš, doc. RNDr. Jiří Bruthans, Ph.D., Jakub Koutník

Tracer tests (indicative or indicator tests, use of markers) are a key technique for determining preferential flow paths and delineating watersheds in karst. They are also widely used to verify flow and determine transport characteristics at contaminated sites. They consist of injecting a known amount of tracer into a sinkhole or well and taking water samples at the locations where tracer is expected to reappear. Tracer tests make it possible to determine not only the flow velocity, but also the volume of mobile water between objects when discharge is measured, and also how many % of the tracer has arrived at the monitored objects, and thus also how many % of the tracer, on the other hand, is heading to unmonitored/unknown places. In the Czech Republic, tracer tests were so far usually carried out mainly with NaCl, especially in connection with water supply facilities. In the USA and neighboring European countries, the most commonly used tracer for decades has been the sodium salt of fluorescein (hereinafter Na-fluorescein) and other fluorescent tracers, as their background concentrations in nature are mostly zero and modern fluorimeters enable to detect tracer concentrations usually in tenths of μg/l, which allows the injection of a very small amount of tracer compared to NaCl, well below visibility with the naked eye. Na-fluorescein is conservative, well soluble, non-toxic. Analysis consists of either direct measurement of fluorescence with field fluorimeters or sampling and laboratory analysis on a laboratory fluorimeter. A tracer test with Na-fluorescein in 2021 demonstrated the rapid flow of water from the Bubovický stream sink in the Český Kras to the springs in Sv. Jan pod Skalou and the surrounding area, and on the contrary refuted the possibility that the water from the sink is connected with the water supply well in Srbsko. The tracer test with Na-fluorescein carried out in 2022 in the Chýnov cave aimed to more accurately characterize the connection of the underground flow with the spring Rutice – drinking water supply for Chýnov town. A positive statement was obtained from the regional public health authorities to carry out the above-mentioned tracer tests. Tracer tests with Na-fluorescein can now be used in the Czech Republic in the same way as in neighboring countries. In conclusion, it can be stated that tracer tests are an effective tool for monitoring groundwater flow not only in karst environments. They can be used to confirm or disprove the rapid connection of sinks, streams, and other objects with drinking water supplies, thereby targeting measures to prevent the possible contamination.

1.12.2022
Mgr. David Hibler, Ing. Jakub Průša

The global pandemic that has swept the world in the last two years has affected most of the population. However, the pandemic has also had an indirect effect on water resources in the water sector. One such example is the almost borderline depletion of groundwater reserves at the Koberovy site, Jablonec nad Nisou district.
The area of interest is interesting from a geological and hydrogeological point of view only because it is located on the border of the Podkrkonoše and Bohemian Cretaceous basins. It is an area with a small catchment area, lower rainfall and also higher groundwater abstractions, i.e. an ideal location for the problem that came at the turn of 2020 and 2021.
In the Koberovy community, groundwater withdrawals from the water supply pumping facility, the drilled well KH-3, increased threefold over the area‘s groundwater table during this period. This has created a significant problem affecting groundwater management in the area. Thanks to the established system of express pumping tests at the intake facilities managed by Severočeské vodovody a kanalizací, a.s. (referred to as SčVK) and field investigations at the site, causes have been identified and solutions proposed that are not ideal from the point of view of the water supply hydrogeologist. As a result, the hydrogeologist recommended adjusting the pumping regime, which was to „buy time“ until the necessary change in the concept of supplying, the area of interest, with drinking water.


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