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Number of results: 6
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Abstract

The article discusses issues related to improving the energy efficiency of heat supply systems. It draws attention to the need to take action not only for large objects and systems, but also for individual buildings and their boiler plants. Heat supply system monitoring allows for the diagnosis of the weakest elements and making decisions leading to the improvement of energy efficiency. In the case of the boiler room where the research was carried out, the results of such monitoring convinced to equip boilers with an additional automatic control system, with an algorithm limiting the number of burner switching cycles and shutdowns. Limiting the number of switching on the burners, as in the case of other combustion and electric devices, has a significant impact on the energy efficiency of the entire system. In addition, it also increases the durability of the devices, and thus reduces costs of servicing and repairs. The simplest control algorithms, often used in controllers installed in the boiler units, do not provide optimization in this respect. The external device used has allowed the number of burners on and off cycles to be limited while maintaining the quality of the heat supply to the heating installation and the heat treatment system.

The material also presents other ways to improve the energy efficiency of the heat supply system in existing multi-family buildings.

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Authors and Affiliations

Grzegorz Bartnicki
Bogdan Nowak
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Abstract

In Poland, it often happens that construction objects are subject to demolition work for different reasons. Demolition, according the Construction Law, is defined as a type of construction works and, as such, represents a particular type of construction project. As in other construction projects, a very important phase, in addition to execution of the works, is to prepare, design and plan demolition works. Some demolition activities are covered by appropriate regulations and can be described as typical. On the other hand the technical side of demolition works depends on many factors such as: the type of building, its age, technical condition, type of construction, etc. This article covers the analysis of the stages and tasks in the preparatory phase of the building demolition. This work will also present a description of the tasks carried out during the demolition works based on the example of a historic tenement house located in Krakow. This analysis aims to identify implementation problems and sources of risk that may occur during this type of construction work.

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Authors and Affiliations

A. Sobotka
A. Radziejowska
J. Czaja
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Abstract

Control of the technological processes of coal enrichment takes place in the presence of wide disturbances. Thus, one of the basic tasks of the coal enrichment process control systems is the stabilization of coal quality parameters at a preset level. An important problem is the choice of the controller which is robust for a variety of disturbances. The tuning of the controller parameters is no less important in the control process . Many methods of tuning the controller use the dynamic characteristics of the controlled process (dynamic model of the controlled object). Based on many studies it was found that the dynamics of many processes of coal enrichment can be represented by a dynamic model with properties of the inertial element with a time delay. The identification of object parameters (including the time constant) in industrial conditions is usually performed during normal operation (with the influence of disturbances) from this reason, determined parameters of the dynamic model may differ from the parameters of the actual process. The control system with controller parameters tuned on the basis of such a model may not satisfy the assumed control quality requirements.

In the paper, the analysis of the influence of changes in object model parameters in the course of the controlled value has been carried out. Research on the controller settings calculated according to parameters T and τ were carried out on objects with other parameter values. In the studies, a sensitivity analysis method was used. The sensitivity analysis for the three methods of tuning the PI controller for the coal enrichment processes control systems characterized by dynamic properties of the inertial element with time delay has been presented. Considerations are performed at various parameters of the object on the basis of the response of the control system for a constant value of set point. The assessment of considered tuning methods based on selected indices of control quality have been implemented.

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Authors and Affiliations

Roman Kaula
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Abstract

The volatility of raw material prices and the rising prices of CO2 emission allowances when using fossil fuels to produce electricity and heat are still relevant problems for owners of generating units. The decision-making tools are used in the fuel purchase process. However, these tools should also consider environmental issues.
The article’s main objective is a quantitative analysis of the potential for reducing costs associated with supplying and using hard coal in public power plants as a result of considering the costs of environmental protection and CO2 emission allowances in the process of planning this fuel supply. A mathematical model was developed to optimize the supply of hard coal for the power industry. The tool and elaborated research scenarios made it possible to calculate and analyze the impact of considering the costs of emissions of harmful substances into the environment and CO2 emission allowances on the planning of coal supplies and the reduction of costs related to acquiring and using coal by public power plants. The calculation results were presented on the example of the Polish power sector.
The model’s results confirm that the appropriate selection of coals, taking into account the quality parameters determining the amount of emissions of harmful substances, reduces the amount of these emissions and the total costs of acquiring and using coal in electricity production. However, depending on the considered scenario, the scale of this impact varies. The results of the optimization of coal supplies to power plants and their proper interpretation may constitute an important contribution to making management decisions in energy companies.
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Authors and Affiliations

Marcin Malec
1
ORCID: ORCID

  1. Mineral and Energy Economy Research Institute, Polish Academy of Sciences, Kraków, Poland
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Abstract

Artykuł omawia historię powstania nadwiślańskiego bulwaru w Warszawie – Wybrzeża Kościuszkowskiego. Przedstawione zostały dzieje urbanizacji tego fragmentu miasta, zaprezentowane pierwsze znaczące budowle, wzniesione przed I wojną światową. W artykule dużo miejsca poświęcono także historii rozwoju fragmentu Powiśla, terenu położonego między ulicą Tamka i ulicą Czerwonego Krzyża. Opisane zostało przekształcenie Powiśla w latach 30. XX w. z zaniedbanej peryferyjnej dzielnicy, przeprowadzone dzięki warszawskim urbanistom i władzom miejskim, w jeden z bardziej reprezentacyjnych fragmentów stolicy. W tej pracy starano się zwrócić uwagę na momenty przełomowe, decydujące o przyspieszeniu procesów urbanizacyjnych Powiśla takich, jak: budowa Mostu Poniatowskiego czy ogłoszenie przez prezydenta miasta, Stefana Starzyńskiego programu „Warszawa frontem do Wisły”. Oprócz zaprezentowania projektów i budowli w artykule przedstawiono także szersze zjawiska kulturowe, związane z modernizacją Powiśla i rozbudową nabrzeży przy Wybrzeżu Kościuszkowskim. Pokazano np. jak teren ten wykorzystywano do politycznych wieców, opisano również nadwiślańskie miejsca sportu i rekreacji.
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Authors and Affiliations

Filip Burno
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Abstract

A project containing suggested amendments to the act of 2010 regulating the work of Commission for Research Integrity (CIR) has been forwarded to the Ministry of Education and Science In August 2022 – no decision has been communicated yet. In April 2022 CIR met with President of PAS prof. J. Duszyński. Current organizational and legislative issues have been discussed as well as means to strenghten the work of CRI. A meeting between CRI and Council for Scientific Excellence was held on 1 August 2022 which dealt with the need to modify the legislation relevant for promotion to full professorship. As pointed out earlier by CRI referees should have access to complete scientific output of a candidate (and not only to its fragments selected by a candidate). In addition, the evaluation should also include ethical aspects of a candidate scientific activity.
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Authors and Affiliations

Andrzej Górski
1
Mieczysław Grabianowski
2

  1. przewodniczący Komisji do sprawEtyki w Nauce
  2. dyrektor Gabinetu Prezesa PAN

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