The article presents the results of surveys to assess the attractiveness of centralized heat supply systems in comparison with other heat sources. The heat source is an important element of the heat supply system which determines heating costs, comfort and environmental impact. The decision on the choice of the type of heat supply system is usually made by the investor or designer. Sometimes the equipment supplier or contractor has a part in this decision. The choice can be influenced by many different factors, also resulting from the specific location of the building. This is only partly determined by local law in the form of a local spatial development plan. the technical conditions (i.e. availability of heating or gas network), economic and financial, as well as much more subjective factors, such as the designer’s or contractor’s preference are also important. Aversion to district heating is growing, even when there are favorable conditions and the possibility of connecting the building to the heating network. Instead, a gas boiler or electrically powered heat pump is selected. This raises the question of whether such decisions are right and how they can be justified. As a research method, surveys were used, which were conducted among people who already have or will have an impact on design and investment decisions in the near future. The obtained results confirmed a large interest in district heating, appreciating their advantages in comparison with other methods of heat generation. The respondents also had the disadvantages that may lead to the use of an alternative methods of heat supplying in mind.

Experimental and numerical study of the steady-state cyclonic vortex from isolated heat source in a rotating fluid layer is described. The structure of laboratory cyclonic vortex is similar to the typical structure of tropical cyclones from observational data and numerical modelling including secondary flows in the boundary layer. Differential characteristics of the flow were studied by numerical simulation using CFD software FlowVision. Helicity distribution in rotating fluid layer with localized heat source was analysed. Two mechanisms which play role in helicity generation are found. The first one is the strong correlation of cyclonic vortex and intensive upward motion in the central part of the vessel. The second one is due to large gradients of velocity on the periphery. The integral helicity in the considered case is substantial and its relative level is high.

In the paper the use of the artificial neural network to the control of the work of heat treating equipment for the long axisymmetric steel

elements with variable diameters is presented. It is assumed that the velocity of the heat source is modified in the process and is in real

time updated according to the current diameter. The measurement of the diameter is performed at a constant distance from the heat source

(∆z = 0). The main task of the model is control the assumed values of temperature at constant parameters of the heat source such as radius

and power. Therefore the parameter of the process controlled by the artificial neural network is the velocity of the heat source. The input

data of the network are the values of temperature and the radius of the heated element. The learning, testing and validation sets were

determined by using the equation of steady heat transfer process with a convective term. To verify the possibilities of the presented

algorithm, based on the solve of the unsteady heat conduction with finite element method, a numerical simulation is performed. The

calculations confirm the effectiveness of use of the presented solution, in order to obtain for example the constant depth of the heat

affected zone for the geometrically variable hardened axisymmetric objects.