The article simulates the impact of the complex application of energy-saving measures on the energy efficiency indicators of a public brick building. During modeling, the economic factor – capital investment in energy saving measures – was taken into account. Similar simulations are carried out during energy audits of various types of buildings. Performing energy audits of residential and public buildings in the city is, in accordance with the Law of Ukraine “On Energy Efficiency”, an important part of Ukraine’s energy conservation policy. Energy audits are required for: a) development of an energy certificate, which is required for many new and existing buildings in accordance with current legislation; b) attraction of funds from the energy efficiency fund and other funds for the needs of thermal modernization; c) obtaining reasonable indicators that will allow building owners to make energy-efficient decisions. The energy audit report contains three stages: the stage of obtaining information, the stage of analyzing information and developing energy-saving recommendations, and the stage of technical and economic substantiation of the proposed energy-saving recommendations. At the first stage, energy auditors collect raw data about buildings. Existing buildings are often characterized by the lack of insulation of opaque enclosing structures, the presence of translucent enclosing structures, the reduced heat transfer supports of which are significantly lower than the minimum permissible values, and outdated sources of heat supply. During the second stage, mathematical models are developed that allow obtaining technical and economic indicators of energy saving measures. The third stage is the substantiation of optimal measures that must satisfy technical and economic constraints. The work analyzed the dependence of the general indicator of specific energy consumption during heating and cooling of a two-story brick public building under the condition of modernization of the gas boiler, as well as insulation of the brick facades of the building with polystyrene foam plates of different thicknesses. At the same time, an analysis of both individual and complex application of the specified measures was carried out. General capital investment in thermal modernization was adopted as an economic indicator that sets limits on energy saving measures. As a result of the modeling, it was established that in order to determine the optimal measures to increase the energy efficiency of the building, it is necessary to use optimization mathematical devices that take into account the existing restrictions and can be integrated into mathematical models that calculate the basic level of energy consumption in compliance with the normative parameters of the building’s operation.

It is shown that the use of solid biomass as a renewable energy source is relevant for the production of thermal energy and electrical energy. but the burning of biomass is accompanied by the release of a significant amount of ash into the environment. The need to organize the primary cleaning of waste gases of heat generators in cyclone dust collectors has been established. The stages of solving problems of aerodynamics and heat transfer in the SolidWorks Flow Simulation CFD package are described. The nature of the distribution of pressures, velocities of gas and solid particles in cyclone filters, the values of heat transfer coefficients in the flow area, based on which the studies of cyclone efficiency, hydraulic resistance, power of the heat exchanger-utilizer and the temperature of heated water were performed. It was established that an increase in the temperature of the inlet gas stream reduces the efficiency of the cyclone in cleaning highly dispersed ash, the presence of a heat exchange surface increases the resistance of the cyclone, but improves its efficiency in capturing solid particles up to 10 μm in size. The obtained results make it possible to improve the design, reduce the metal content, and find rational modes of operation of cyclones in operating conditions.

The operating conditions of the water-type towel dryer made of polished stainless steel AISI 304 are established, the declared capacity of towel dryers of almost the same design of different manufacturers is compared and a significant discrepancy is revealed; analyzed four methods for determining the nominal heat output of the towel dryer, taking into account the forced movement of the coolant inside the towel dryer, free or forced air movement near the surface of the towel dryer under different boundary conditions in compliance with regulations; modeling of towel dryer operation by means of Flow Simulation software module in SolidWorks; he influence of uncertainty of degree of blackness of a towel dryer surface on nominal thermal power of a towel dryer is investigated; influence of speed of washing of a heat exchange surface of a towel dryer by air on its thermal power is estimated, the received results of researches by four methods are analyzed.