ИННОВАЦИОННЫЕ СИСТЕМЫ ТЕРМОТРАНСФОРМАЦИИ. АНАЛИЗ. СИНТЕЗ. ОПТИМИЗАЦИЯ

The monograph addresses the development of the theoretical foundations for the improvement of thermal transformation technologies for their competitive implementation in the designed and modernized heat and cold supply systems. Modern methods of thermo-economic analysis and optimization of thermal transformers are widely used in the work, the synthesis of their technological schemes is considered. Original methods have been developed for testing the thermodynamic perfection of modern refrigeration machines and heat pumps, as well as evaluating their technical, economic, and environmental indicators when working in heat and cold supply systems. Methods of thermo-economic optimization of steam compressor thermo-transformers using substances of natural origin as a refrigerant are proposed. The book is designed for engineers and scientists in the field of energy and low-temperature technology, and is of interest to graduate students and students of relevant specialties. Indexing:              Монография посвящена развитию теоретических основ совершенствования технологий термотрансформации для их конкурентоспособного внедрения в проектируемые и модернизируемые системы тепло- и хладоснабжения. В работе широко используются современные методы термоэкономического анализа и оптимизации термотрансформаторов, рассмотрены вопросы синтеза их технологических схем. Разработаны оригинальные методики тестирования термодинамического совершенства современных холодильных машин и тепловых насосов, а также оценки их технико-экономических и экологических показателей при работе в системах тепло- и хладоснабжения. Предложены методики термоэкономической оптимизации парокомпрессорных термотрансформаторов, использующих в качестве хладагента вещества природного происхождения. Книга рассчитана на инженерных и научных работников в области энергетики и низкотемпературной техники, представляет интерес для аспирантов и студентов соответствующих специальностей. Індексація:               &nbsp

ТЕРМОЭКОНОМИЧЕСКАЯ ДИАГНОСТИКА И ОПТИМИЗАЦИЯ ПАРОКОМПРЕССОРНЫХ ТЕРМОТРАНСФОРМАТОРОВ

The monograph discusses modern methods of thermoeconomic analysis, diagnostics and optimization of steam compressor thermotransformers for various functional purposes. Examples of solving a whole range of practical problems on the design of vapor-compressor thermotransformers with thermoeconomically justified operating and structural characteristics are given. The monograph is designed for engineers and scientists, is of interest to graduate students and students of energy specialties. Indexing:             В монографии рассмотрены современные методы термоэкономического анализа, диагностики и оптимизации парокомпрессорных термотрансформаторов различного функционального назначения. Приведены примеры решения целого круга практических задач по проектированию парокомпрессорных термотрансформаторов с термоэкономически обоснованными режимными и конструктивными характеристиками. Монография рассчитана на инженерных и научных работников, представляет интерес для аспирантов и студентов энергетических специальностей. Індексація:             &nbsp

FT-IR study of self-association of some hydroperoxides

Self-association of cumyl, tertiary butyl and 3-phenylmethyl hydroperoxides in solutions of n-decane, carbon tetrachloride and chlorobenzene were studied by IR spectroscopy (3100-3700 cm-1, 293-353 K). The experimental data were interpreted by factor analysis and band contour resolution. The di-. and trimerization constants and thermodynamic parameters of self-associates were determined. Intramolecular hydrogen bond of cumyl hydroperoxide was investigated. The conformations of tertiary butyl and cumyl hydroperoxides were studied. The solvent influence on the thermodynamic parameters of hydrogen bond was found. © 2004 Elsevier B.V. All rights reserved

INNOVATIVE THERMAL TRANSFORMATION SYSTEMS. ANALYSIS. SYNTHESIS. OPTIMIZATION

The monograph addresses the development of the theoretical foundations for the improvement of thermal transformation technologies for their competitive implementation in the designed and modernized heat and cold supply systems. Modern methods of thermo-economic analysis and optimization of thermal transformers are widely used in the work, the synthesis of their technological schemes is considered. Original methods have been developed for testing the thermodynamic perfection of modern refrigeration machines and heat pumps, as well as evaluating their technical, economic, and environmental indicators when working in heat and cold supply systems. Methods of thermo-economic optimization of steam compressor thermo-transformers using substances of natural origin as a refrigerant are proposed. The book is designed for engineers and scientists in the field of energy and low-temperature technology, and is of interest to graduate students and students of relevant specialties

THERMOECONOMIC DIAGNOSTICS AND OPTIMIZATION OF STEAM COMPRESSOR THERMOTRANSFORMERS

The monograph discusses modern methods of thermoeconomic analysis, diagnostics and optimization of steam compressor thermotransformers for various functional purposes. Examples of solving a whole range of practical problems on the design of vapor-compressor thermotransformers with thermoeconomically justified operating and structural characteristics are given. The monograph is designed for engineers and scientists, is of interest to graduate students and students of energy specialties

Analysis of the Effect of Thermohydraulic Irreversibility of Processes in the Cycle of a Refrigeration Machine with a Non-azeotropic Mixture of Refrigerants

The object of research is the effect of thermohydraulic irreversibility of energy processes in the cycle of a refrigeration machine using an ozone-safe non-azeotropic mixture as a refrigerant on its energy efficiency. One of the most problematic places during the development and design of such refrigeration machines is that, due to the peculiarities of the thermodynamic properties associated with the different chemical composition of the components, non-azeotropic mixtures are characterized by differences in the equilibrium concentrations of the components in the liquid and vapor phases. This property of non-azeotropic mixtures presents a certain difficulty for their effective application in refrigeration machines and heat pumps. During the study, modern methods of analysis and synthesis of thermodynamic systems are used, based on the application of the theoretical apparatus of technical thermodynamics, thermoeconomics, the theory of heat and mass transfer, as well as elements of the theory of systems engineering. The issue of assessing the energy efficiency of the cycles of refrigeration units operating on a non-azeotropic mixture of refrigerants is considered, taking into account the variability of the composition of the components of the mixture. A method has been developed for the formation of the composition of a multicomponent mixture, taking into account the influence of the non-isobarity of processes in the hydraulic circuit of the refrigerant circulation on the energy efficiency of the refrigeration machine. Based on a numerical experiment, the influence of changes in the concentrations of the components of the mixture R32, R125, R134a on the non-isothermal phase transition in the evaporator and condenser, as well as on pressure losses in the hydraulic circuit elements of an autonomous air conditioner, is established. The effect of friction at a temperature level below ambient temperature on the exergy efficiency of the refrigeration machine is analyzed. An advanced exergy analysis of the refrigeration cycle with a non-azeotropic mixture is carried out, as a result of which the avoidable and unavoidable, as well as the endogenous and exogenous components of the destruction of exergy in the elements are determined. The proposed method, due to its visibility, can significantly simplify the finding of the thermodynamic parameters of the refrigerant at the nodal points of the refrigeration machine cycle during numerical simulation

Thermodynamic Analysis of Air-compression Refrigerating Machine Based on the Exergy Cost Theory

On the basis of the exergy cost theory, a procedure has been developed for carrying out an in-depth thermodynamic analysis of air-compression refrigerating machines and thermal pumps taking into consideration nonequivalence of exergy losses in various links of thermotransformation process and their effect on consumption of exergy supplied to the system. A thermoeconomic model of a single-stage air-compression refrigerating machine was proposed which takes into consideration structural and topological features of the process scheme and interrelation between its elements. For an equivalent mapping of structural and topological features of the refrigerating machine scheme, a parametric flow graph was developed. The procedure uses a matrix form of recording exergy balances which is the most convenient for representation of the thermoeconomic models. In order to obtain reference operating mode of the refrigerating machine, the principle of thermodynamic process idealizing was used. Application of the structural theory of thermoeconomics has made it possible to establish the portion of endogenous and exogenous destruction of exergy in the elements of the refrigerating machine.Numerical implementation of the proposed procedure has made it possible to reveal influence of internal irreversibility in the cycle determined by non-isentropic compression processes in the compressor and expansion in the expander. A significant effect of efficiency of the expansion process in the expander on the exergy efficiency of the air-compression refrigerating machine was established.Influence of the change of ambient temperature on the character of consumption of exergy by each element of the refrigeration machine was estimated. It has been revealed that even a slight change of the ambient temperature significantly affects consumption of “fuel” by each element of the system, while the dependence is linear.Generalized dependences of exergy indicators on variable factors have been obtained which enabled finding of unfavorable operating conditions for equipment with increased energy consumption. It was established that the efficiency factor of the turboexpander has the greatest influence on the change of consumption of exergy of “fuel” in the system

Development of a Vacuum-evaporative Thermotransformer for the Cooling System at a Nuclear Power Plant

The study addresses the development of a method for the optimal design of vacuum-evaporative heat pump plants (HPP) for a cooling system of technological equipment of the second circuit at a nuclear power plant (NPP) using modern methods of thermodynamic analysis and thermoeconomic optimization.We have proposed two circuits for inclusion of a vacuum-evaporative HPP into a cooling system of the second circuit at NPP. The first circuit implies the use of HPP in combination with an existing cooling tower. It makes it possible to cool water additionally from 30 °C to 25 °C after a cooling tower. Only HPP cools water to the required parameters in the second circuit.A thermodynamic model to forecast static characteristics of HPP has been developed. We analyzed thermodynamic properties of water as a refrigerant and evaluated their influence on mode parameters and energy efficiency of a vapor compression cycle. It was established that water fully complies with all environmental safety requirements for operation substances of heat pumps. Its use makes it possible to provide high energy performance of a cycle in comparison with synthetic refrigerants. The problematic aspects of water use include high temperature, which is characteristic of a vapor-water cycle at the end of the compression process. However, it is possible to level the influence of temperature on energy and operational parameters of a plant by using a two-section condenser with utilization of heat from vapor overheating.We selected rational circuit-cycle solutions for a vacuum-evaporative HPP using a graph-analytic apparatus for constructing C-curves. The rational circuit-cycle solutions ensure efficient operation of a plant for cooling of technological equipment of the second circuit at NPP. The system's capital capacity has been estimated as well.We used modeling of thermohydraulic processes in a circulation circuit of a refrigerant, performed thermoeconomic optimization and determined mode-and-structural characteristics of a plant that correspond to the minimum of resulting costs during its operation