The researches results of thermotechnical and environmental parameters of emissions from chimneys of gas-fired boiler plants equipped with systems for deep heat recovery of exhaust gas are presented. The issues of the expediency of using heat methods for preventing condensation formation in chimneys to improve their environmental friendliness are considered. These are methods of partial bypassing of boiler exhaust gases past the heat recovery equipment, predrying the exhaust gases cooled after heat recovery in heat exchangers-gas heaters and mixing dry and heated air from the boiler room air heater to these gases. The efficiency of using these methods in order to improve the environmental performance of chimneys is analyzed. A relative decrease in the maximum surface concentration of such harmful emissions as nitrogen and carbon oxides due to the use of these heat methods has been determined. Comparison of the effectiveness of the application of these methods to improve the environmental friendliness of the considered chimneys is carried out. It is shown that the proposed methods used for anticorrosion protection of chimneys of boiler plants when using heat recovery technologies with deep cooling of flue gases contribute to an increase in the environmental friendliness of these chimneys.

The results of the analysis of exergy losses in separate elements of the installation containing a gas-fired boiler and the combined heat recovery system for heating water and blast air are resulted. It is noted that a complex technique combining the methods of exergy analysis with one of the methods of the theory linear systems is used to determine exergy losses, namely, the method of RP-representation thermodynamic balances in matrix form. When implementing this technique for separate elements of the heat recovery system, the balances of mass, energy and exergy are recorded in matrix form. On the basis of matrix balances the input matrix by means of which total exergy losses in heat recovery system at various operating modes of a boiler are calculated is defined. The results of calculating the relative contribution of exergy losses in each element of the heat recovery system to the total irreversibility of processes in the system at different operating modes of the boiler are analyzed. It is noted that the smallest losses in the main elements of the heat recovery system occur when the boiler capacity is up to 55 % of the installed capacity.

The paper proposes new circuit solutions for dual-fuel monar gas-steam plants (DMGSP), which provide an increase in the efficiency of electricity production in these plants by replacing the use of natural gas and increasing the share of generating "energy" steam by including an additional source of generation in the technological scheme steam - "preboiler", in which steam generation occurs as a result of the use of chemical energy of low-grade solid or liquid fuels - substitutes for natural gas of low or medium calorific value. DMGSPs are considered in two variants of operation of their utilization circuit: under conditions of heating and evaporation of feeding water, or only heating of this water. The results of calculations of the effectiveness of the implementation of these schemes on the basis of a monar gas turbine plant in comparison with the basic installation "VODOLEY" and a gas turbine plant of a simple scheme are presented.

The basic positions of the enthalpy-entropy methodology of thermodynamic modeling of processes in gas turbine units (GTUs) and combined power plants on basis GTUs are presented. The main requirements and conditions of this methodology are formulated, they allows the construction of a sequential (without iterations) algorithm for the computational diagnostics of the thermodynamic parameters of the GTU cycle, which includes the calculation blocks for the compressor, combustion chamber, turbine, and exhaust tube of the GTU. The obtained regression equations are presented. The use of these equations simplifies of the procedure for evaluating the thermodynamic parameters of the components at the nodal points of the cycle. The advantages of the proposed methodology in comparison with the traditional thermal-entropy methodology are indicated.

Доктор технических наук, профессор Н. М. Ф и а л к о Доктор технических наук, профессор, заведующая отделом, заслуженный деятель науки и техники, член-корреспондент НАН Украины*