The article focuses on systems analysis in identifying optimal areas for using distributed energy sources in the agro-industrial complex. Applying a systems approach enables a comprehensive assessment of various aspects of solar energy, wind energy, hydropower systems and integrated power plants that provide autonomous energy supplies. The research methodology includes a functional–structural approach that helps to assess the internal characteristics of systems, allowing for a deeper understanding of their structure and functions. This, in turn, leads to the creation of different models reflecting specific elements and relationships in energy systems. The main point is to take into account the level of functional and structural perfection, which helps to more accurately determine the areas where the introduction of renewable energy sources will be most effective, taking into account the specifics and needs of the agro-industrial complex. This approach not only contributes to a more optimal allocation of resources but also improves the sustainability and efficiency of energy systems in the face of a changing climate and the growing demand for environmental technologies.

The process of sublimation drying of berries provided, this is the drying method along the berry the humidity is reduced to 2-5%. The dryer is conditional consists of two blocks - refrigeration and sublimation unit. At room temperature the product is placed in the drying chamber. Equipment after connection, vacuum pump in the chamber reduces the pressure to 10-30 Pa. When a vacuum is created and free product due to evaporation of moisture leads to freezing. Most of the moisture is converted into ice crystals, and then the sublimation process begins. This equipment uses 404 a freon. Temperature to register 8 channel OVEN TRM138 RS-485 temperature meter was used. Of the product to measure weight every 30 minutes removed from the chamber Vibra HT 224RCE was weighed on an analytical balance. The experiment was performed with three types of berries: strawberries; currants and raspberries. Experience during the temperatures on the surface of the berries, inside the chamber and the mass of the product were measured. Duration of drying as a criterion of effective mode, energy expenses and quality indicators of dried berries were determined. The effective sublimation time was 4.5 hours. Inside the chamber at a pressure of (20 ± 5) Pa, at a temperature of (-42 ± 2) 0С, general freezing and sublimation time not more than 5 hours, the total drying time is 8 hours. The initial weight of strawberries decreased by 36%, currants by 28% and raspberries by 27.4%. Drying should be stopped when the chamber temperature reaches 40 ° C.

An analysis of the current state of development in the agro-industrial complex (AIC) has established that freeze-drying is the most effective method for processing raw materials entering the drying stage. However, this drying method is hindered by the lack of modern, high-performance, energy-efficient drying technologies and equipment. The production of freeze-dried agricultural products will stimulate the development of AIC sectors. The implementation scheme of an automatic control system for a vacuum freeze-drying unit is considered, representing a promising and environmentally friendly direction in the processing of agricultural products. The drying equipment includes the following components and systems: a drying chamber, a cooling system, a vacuum pump, a control system, and a heating system. The product is placed on shelves in the drying chamber and frozen to a temperature that ensures the removal of 75-80% of the moisture contained in the product. The vacuum pump creates a pressure of 10-30 Pa and evacuates the spent air from the sublimator. Water vapor condensation occurs in the desublimator, and at the final stage of the drying process, the heating elements are activated to remove the remaining moisture. To validate the reliability of controlling the operating modes of the sublimator, experimental studies were conducted on the temperature dependence of the product on the surface and in the center over time. The graphs show temperature changes on the surface and in the center of the product throughout the drying process. The research results indicate that at a pressure of 20±5 Pa, the desublimator temperature should be below -20°C. The surface temperature of the product during the sublimation stage should be within the range of -25±5°C. Drying is completed when the chamber temperature reaches no more than 40°C, and the surface temperature of the product is around 30°C.

В современных тепловых насосах, как и в холодильниках, применяется камерный принцип размещения основных компонентов, при котором испаритель изолируется от компрессора путем их раздельного размещения с каждой стороны камеры. То есть внутри камеры был установлен испаритель, а компрессор - снаружи. В статье экспериментально изучается гипотеза самоохлаждения компрессора теплового насоса путем обеспечения теплообмена между поверхностью корпуса компрессора и поверхностью испарителя. Автор предполагает, что внешний тепловой поток, вращающийся от поверхности компрессора до испарителя, сопровождается основным внутренним тепловым потоком, что приводит к общему положительному результату. Особое внимание уделяется варианту концентрационного расположения корпусов компрессора между собой и теплообменнику испарителя. Обосновывается прогноз влияния на процессы теплообмена размещения компрессора по центру полости испарителя или с смещением от Центра. Для этого конструкция испарителя выполняется в виде полого цилиндра с компрессором в внутренней полости корпуса испарителя. Теплоизмерения показали поглощение испарителя избыточного тепла компрессора, понижение температуры нагрева корпуса и головки камеры сжатия компрессора. Исследования подтвердили повышение тепловой и охлаждающей производительности теплового насоса и возможность обеспечения самохлаждения компрессора.

The article examines a “variable-frequency drive–induction motor” system of a pneumatic conveying device from the perspective of improving energy efficiency and enhancing the dynamic characteristics of the electric drive. A structural diagram of the frequency-controlled induction electric drive is presented, transfer functions of the system elements are derived, and its stability is analyzed. The study of the electric drive dynamics is carried out based on mathematical modeling in the MATLAB environment using both symbolic and numerical methods. It is established that the voltage stabilization system of the frequency converter ensures a stable operating mode of the induction motor for various values of the controller parameters. The work also includes the synthesis of control system parameters aimed at minimizing energy consumption. An objective function of energy costs is obtained, and optimal parameters of the frequency converter voltage controller are determined. Numerical modeling demonstrated a reduction in power consumption from 4 kW to 2.89 kW, confirming the effectiveness of the proposed approach. The results of the study indicate that the use of a frequency-controlled electric drive in pneumatic conveying systems makes it possible to increase energy efficiency, improve transient processes, and ensure stable system operation under varying loads.