The main task in the development of concentrating systems is in reducing the inhomogeneous distribution of illumination over the focal spot, which determines the distribution of concentrated radiation on the receiver, which affects the efficiency of heat and photo converters. (Research purpose) The research purpose is in modeling for calculation, construction manufacturing and research of characteristics of a thermal photovoltaic module with specified energy parameters. (Materials and methods) The article considers new thermal photovoltaic modules that include photodetectors and concentrators that provide efficient conversion of solar energy into heat. The research is based on mathematical modeling techniques using the laws of photoelectricity, geometric optics, and heat and mass transfer. The computer-aided design system COMPASS-3D was used to create a prototype model of the solar module, and the FDM 3D printing technology was used to produce the resulting CAD models. Authors conducted bench and field tests of components and complexes of solar power systems in order to clarify the design parameters. (Results and discussion) During the study of a developed solar module with parabolic concentrators and a discrete photodetector with asymmetric profile, with a system of the coolant flow, physical and mathematical models on the basis of which was calculated: the structural parameters; the distribution of concentration of solar radiation across the width of the photodetector; dependences of the distribution of the heating temperature of the coolant over the profile of the photodetector. Authors designed a layout of the basic thermal photovoltaic module, in which the rounded lower part of the rotary rack fixed on the axis allows to create a rotation in the axial direction of the photodetector holders within ±20 degrees with a mechanism for fixing the adjusted position. (Conclusions) Based on the alignment carried out on the stand, the identical location of the receivers of concentrated solar radiation relative to the concentrators in the installation is preserved.

Modern application of chemical plant protection products and liquid mineral fertilizers requires a comprehensive approach in compliance with all agricultural standards. Under-watering or overdosing of the introduced fertilizers can adversely affect the yield. Sprayers used on agricultural machines must be carefully selected and tested. (Research purpose) The research purpose is in analyzing the features of testing sprayers used on agricultural machines. (Materials and methods) The article presents reviewed data on the use of various methods of sprayer testing. Authors studied open sources as research materials and conducted a comparative analysis of the information. (Results and discussion) The article describes successive stages and test methods. The initial stage of testing sprayers is to determine the size (diameter) of drops at a certain pressure (1.5-3 bar) of the pump system. The liquid demolition directly depends on the size of the drop. Authors used the method of distribution of the solution into measuring cups on specialized test benches to determine the discharge rate. The article presents an example of the resulting table for testing sprayers.

The most common failures of piston diaphragm pumps are described and analyzed. Based on the data obtained, a generalized table has been prepared, including the name of the malfunctions, the reason for their occurrence and remedies. In the future, these data can serve as the main one when organizing the repair station of piston diaphragm pumps.