The paper studies the labyrinth seals of centrifugal compressor profit-proved stages using modern methods of numerical and physical modeling of the centrifugal compressor stages. A series of studies of the effect of operational and geometrical parameters on the maze, namely the quantities of the packed differential pressure, speed, fluid, geometric parameters of the seal, the magnitude of the eccentricity and radial clearance swirl flow at the inlet of a seal, etc. The technique of physical modeling seal has been specified. Research was conducted in two phases: numerical simulation using complex software Flow Vision and receiving data on a universal test bench to study the labyrinth seals.. A three-dimensional model of the labyrinth seal has been created, its verification by "known data has been held.. Integral characteristics in the form of distribution of flow velocities and pressures, flow visualization were obtained. Results of studies made ​​it possible to refine the workflow and introduce amendments to the known calculation formula for a more accurate calculation of leakage through the seal, subject to a number of additional factors that were not previously taken into account

Abstract. The present study provides the overview of Maisotsenko Cycle (M-Cycle) applications for gas cooling in compressor systems. Various schemes of gas cooling systems are considered regarding to their thermal efficiency and cooling capacity. Preliminary calculation of M-cycle HMX has been conducted. It is found that M-cycle HMX scheme allows to brake the limit of the ambient wet bulb temperature for evaporative cooling. It has demonstrated that a compact integrated heat and moisture exchange process can cool product fluid to the level below the ambient wet bulb temperature, even to the level of dew point temperature of the incoming air with substantially lower water and energy consumption requirements. IntroductionGas compression and transportation is one of the most energy consuming technologies in the world. Compressors are a vital link in the conversion of raw materials into refined products. Compressors also handle economical use and transformation of energy from one form into another. They are used for the extraction of metals and minerals in mining operations, for the conservation of energy in natural gas reinjection plants, for secondary recovery processes in oil fields, for the utilization of new energy sources such as shale oil and tar sands, for furnishing utility or reaction air, for oxygen and reaction gases in almost any process, for process chemical and petrochemical plants, and for the separation and liquefaction of gases in air separation plants and in LPG and LNG plants. The economy and feasibility of all these applications depend on the reliability of compressors and the capability of the compressors selected to handle a given gas at the desired capacity [1]. Since, value of specific work for all compressors is determined by several factors as: specific heat ratio k, specific gas constant R, pressure ratio  and inlet temperature T in . As a rule, all the enumerated factors except the inlet temperature are defined by the initial conditions and/or performance specification for the designed compressor. That is why inlet temperature reduction remains the most feasible way to reduce compressors' specific work.There are a lot of approaches to reduce T in value (depending on the place of cooling):

At the present stage of social development, the need for rational use of energy resources of the planet is particularly acute. Most countries have already faced the problem of the energy crisis. An appropriate way to solve this problem is the utilization of secondary energy resources. With the help of turbine generators, it is possible to reduce the pressure and utilize the potential energy of excess pressure of gas or vapours to produce electricity. Such units can be created based on a jet reaction turbine. The study aims to assess the impact of the degree of off-design of the traction nozzle on the efficiency of the jet reactive turbine. The analysis of the factors influencing the efficiency of the jet reaction turbine is carried out in the work. The obtained efficiency rate for the jet reactive turbine depending on the given dimensionless velocity of λout t at the inlet pressure of the inlet nozzle of 2, 4, 6 and 10 MPa in the design mode (at the degree of off-design of S = 1) and in the off-design modes of operation ( S> 1). Graphical dependencies of the jet reaction turbine efficiency rate on the given circular velocity of the impeller are constructed (U− = 0… 0.7). The research shows that with increasing pressure at the inlet to the inlet nozzle, the efficiency rate of the turbine increases, and the optimum of the efficiency rate is shifted towards the increase of the given circular velocity of the impeller, both in the design and off-design operating modes. It is found that the greatest value of the efficiency rate is acquired at the design mode of operation of the traction nozzle, i.e. at S = 1.

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Представлены результаты аналитического и физического моделирования лабиринтного уплотнения. Аналитическое исследование проводилось с использованием теории планирования эксперимента и теории идентификации математической модели, а физическоена специально разработанном унифицированном экспериментальном стенде. Выполнен ряд исследований влияния режимных и некоторых геометрических параметров на течение в лабиринтном уплотнении. Показано влияние исследуемых параметров на расходные характеристики уплотнения. Предложена математическая модель условного коэффициента расхода уплотнения основанная на представлении гидравлического сопротивления лабиринтного уплотнения как суммы местных сопротивлений элементов, описываемых аналитическими выражениями. Решена задача идентификации модели с использованием опытных данных. Полученная модель применима в диапазоне геометрических и режимных параметров имевших место в опытах. Ключевые слова: лабиринтное уплотнение, коэффициент расхода, математическая модель, метод идентификации.