Resource and Energy Efficient Method of Dried Fish Production

The authors of the article propose a method of convective dehydration of fish products, which has an intermittent nature of implementation. The dehydration process consists of the continuous initial phase and following combined periods consisting of phases of drying and relaxation of dehydrated surface layer of the raw material. The necessity of applying relaxation is due to the fact that during the drying process the surface layers that have lost some of the moisture are significantly densified. The size of the capillaries for moisture passing through the surface layers is reduced. Near the surface a layer is formed, which lacks the significant mass of moisture and has low diffusion properties. As a result, the dehydration process of the entire sample slows down. The rational use of relaxation leads to restoring the moisture-conducting properties of the surface layer of fish. The supply of electrical energy to the heating elements is stopped during the relaxation. The minimum circulation rate of the drying agent is maintained in the drying installation. Fresh air with a lower temperature and higher relative humidity than the drying agent is supplied to the drying agent. The conditions in the drying installation restrain external mass transfer and facilitate to the relaxation of the dehydrated surface layer, that is, to the redistribution of moisture in the thickness of the fish. The proposed method of dehydration of fish raw material reduces the cost of electric energy in the production of dried products and provides more rational coolant usage. The final fish products have more attractive appearance due to reduction of tissue deformation as a result of applying the relaxation of dehydrated surface layer

Development of an Autoclave Thermal Processes Model for the Simulator of Canned Food Sterilization Process

The article describes an autoclave thermal processes model, which is used for the simulator of canned food sterilization process. The simulator is based on a simulation model that adequately describes the reaction of the autoclave to the actions of the control system and the operator of the sterilization unit. The model’s parameters were obtained by means of experimental data processing. The computer program ”autoclave Model” for simulating sterilization process in the steam and water environment is described. The examples of the canned food’s manual control sterilization modeling are shown. The results of numerical mathematical modeling of canned food sterilization processes in the autoclave showed a high degree of the implemented process models quality of approximation. The calculation schemes done as a result of the mathematical models creation were used to develop a hardwaresoftware complex of the sterilization process simulator. The increase of training level on carrying out process of canned goods sterilization will be provided as a result of designing the simulator of sterilization process in educational process. Consequently reducing defects in production and improving the quality of canned products are expected

Modified Criterion for Economic Efficiency Estimation of Heat Pumps

In this work the cost-effectiveness of coal mine waste water low potential heat utilization and integration in the enterprise local heating network by the bivalent parallel scheme is investigated. It is shown that the additive criterion of economic efficiency is not always sensitive to the target value because of the reason of non-linear coupling between the arguments of the target function. Several cases were considered from the viewpoint of cost-effectiveness criterion. Moreover, the arguments of the target function are also nonlinear, depending on technological parameters of the heat pump (HP) equipment. As a more effective criteria were proposed the modified canonical additive-multiplicative function and Kolmogorov-Gabor polynomial function to obtain the generalized multivariate estimation of alternatives in two stages procedure

Single-Phase Flow of Non-Newtonian Fluids in Porous Media

The study of flow of non-Newtonian fluids in porous media is very important and serves a wide variety of practical applications in processes such as enhanced oil recovery from underground reservoirs, filtration of polymer solutions and soil remediation through the removal of liquid pollutants. These fluids occur in diverse natural and synthetic forms and can be regarded as the rule rather than the exception. They show very complex strain and time dependent behavior and may have initial yield-stress. Their common feature is that they do not obey the simple Newtonian relation of proportionality between stress and rate of deformation. Non-Newtonian fluids are generally classified into three main categories: time-independent whose strain rate solely depends on the instantaneous stress, time-dependent whose strain rate is a function of both magnitude and duration of the applied stress and viscoelastic which shows partial elastic recovery on removal of the deforming stress and usually demonstrates both time and strain dependency. In this article the key aspects of these fluids are reviewed with particular emphasis on single-phase flow through porous media. The four main approaches for describing the flow in porous media are examined and assessed. These are: continuum models, bundle of tubes models, numerical methods and pore-scale network modeling.Comment: 94 pages, 12 figures, 1 tabl

Conceptual model adaptive control system complex with distributed energy sources

Разработаны структура концептуальной модели системы адаптивного управления комплексом зданий с распределенными энергоисточниками (КЗРЭ), алгоритм оценки эффективности управления КЗРЭ и сформулированы общие требования к системе, позволяющие в реальном времени отслеживать изменения на производстве и в окружающей среде.Розроблено структура концептуальної моделі системи адаптивного управління комплексом будівель з розподіленими енергоджерела (КЗРЕ), алгоритм оцінки ефективності управління КЗРЕ і сформульовані загальні вимоги до системи, що дозволяють в реальному часі відстежувати зміни на виробництві та в навколишньому середовищі.Developed structure of the conceptual model of adaptive control of the complex of buildings with distributed energy sources (KZRE) algorithm for estimating the efficiency of management and KZRE formulate general requirements for a system allowing real- time tracking of changes in the workplace and in the environment