Browsing by Author "Stoyanov Y."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Modelling and numerical simulation of fire in a coffee storage hall
    (2021-11-22) Krumov K.; Penkova N.; Mladenov B.; Stoyanov Y.
    An approach for modelling of fire in halls at solid materials burning, based on gas phase combustion models in ANSYS/CFX, is proposed. The models are suitable for quick prediction of the flue gases distribution and thermal loads on the building envelopes at a design stage. They was applied for numerical simulation of such processes in a coffee storage hall at different fire positions and forced anti-smoke ventilation. The thermal, fluid flow and concentration field were obtained at the modelled scenarios. Maximal thermal loads on the building envelopes are established at the case of fire near their non-streamlined parts.
  • No Thumbnail Available
    Item
    Modelling and numerical simulation of the heat transfer and natural ventilation in storage halls
    (2020-11-18) Penkova N.; Krumov K.; Mladenov B.; Stoyanov Y.
    An algorithm for modelling of the heat transfer in storage halls at different combinations of open doors and smoke vents is developed. The models allow numerical simulations of velocity, pressure and temperature fields in the halls in cases of transient and steady state conditions, taking into account the indoor buoyancy, heat sources, heat transfer through the building envelopes and outdoor wind pressures. The models are solved numerically via finite volume method in order to estimate the necessity of additional heating at a design stage of a courier logistic storage hall, situated in the temperate climate zone, at the hardest winter conditions of the region. Recommendations about the organization of the heating and the cargo input are done based on the analyses of the fluid flow and thermal fields at the modelled scenarios.
  • No Thumbnail Available
    Item
    Performance of diffusion absorption refrigerators at variable power input
    (2024-01-01) Stoyanov Y.; Penkova N.; Krumov K.
    Absorption refrigerators have been used in recent decades for utilization of waste or solar energy to produce heat or cold for industrial purposes or to condition the microclimate in buildings. Although these units are designed at nominal power input in the generator, they can also operate at variable parameters of the heat source, which is possible in the real situations. An experimental determination of the operating range and the performance of a diffusion absorption refrigerator at heat pump and refrigeration mode were carried out in the present study. The results are useful for predicting the efficiency and the effectiveness of such systems at variable heat source capacities.