The concept of the creation of universal smart machines for power systems and critical infrastructure is discussed herein in terms of digital economy requirements. The functional requirements for a universal smart machine for sustainable energy systems are systematized based on a comparative analysis of technology. The requirements determine the approaches to the implementation of software, hardware and design solutions that provide diagnostics and monitoring of the energy state of infrastructures, systems for individual and collective power supply, life support systems of buildings, the state of household appliances, IoT devices, and devices of the housing and utilities sector. The recommendations on the constructive implementation of smart machines are given, making it possible to improve the existing approaches to quality assessment of the services provided in the energy industry. The concept of universal smart machines opens up the opportunities to increase the efficiency of providing the industry and households with a new type of information management services in the field of control over energy infrastructure as one of the main components of the digital economy.

One of the most important problems of creating new and also modernizing and operating the existing industrial equipment is to provide it with technical diagnostic tools. In modern systems, most diagnostic problems are solved by vibration monitoring methods, and they form the basis of this process. For several years already, when creating new responsible equipment, many manufacturers have completed it with monitoring and diagnostic systems, often integrating them functionally with automatic control systems. This paper discusses the methods of servicing industrial equipment, focusing on predictive maintenance, also known as actual maintenance (maintenance according to the actual technical condition).The rationale for the use of wireless systems for data collection and processing is presented. The principles of constructing wireless sensor networks and the data transmission protocols used to collect statistical information on the state of the elements of industrial equipment, depending on the field of application, are analyzed. The purpose of the study is to substantiate the feasibility of using wireless sensor networks as technical diagnostic tools from both economic and technical points of view. The result is the proposed concept of the predictive maintenance system. The paper substantiates the model of optimization of predic-tive repair using wireless sensor networks. This approach is based on minimizing the costs of maintenance of equipment. The presented concept of a system of predictive maintenance on the basis of sensor networks allows real-time analysis of the state of equipment. The approach allows implementing smart management of technologies in companies for ensuring stability of functioning.

The article presents the concept of innovative technology used to store refrigerated containers in port terminals or on ships that aims to reduce the energy consumption. The idea of new technology to store refrigerated containers was described on port's terminal example. According to set assumptions, the mathematical heatbalance model of containers stored on yard has been proposed to calculate the savings, as well as the effects of such solution usage have been shown. The results of preliminary calculations were compared to results of experimental verification conducted in the laboratory and based on the approximate model. Obtained results both calculations and experimental verification proved the effectiveness of proposed concept; however, the experimental results indicate smaller savings, then the calculated one.

ABSTRACT

Refrigerators play an important role in perishable goods supply chains and are expected to operate efficiently. Thermoelectric refrigerators need specific criteria for assessing their energy efficiency. The existing criteria do not take into account the insulation properties of a refrigerator cabinet, which results in a low credibility of the assessment of energy parameters of thermoelectric coolers. The aim of the research was to develop and approve a new universal criterion for assessing the energy efficiency of stationary thermoelectric refrigerators used in supply chains. It was proposed to replace the known criterion of specific power consumption with a new indicator Pk, that takes into account the overall thermal transfer coefficient of the refrigerator cabinet. Based on experimental studies, the approval of the proposed indicator was carried out on the example of a comparative analysis of four thermoelectric refrigerators from different manufacturers. The indicator application resulted in changes in ranking of the examined refrigerators. It was found that the proposed criterion allows us to assess the effectiveness of a thermoelectric cold source more adequately, including the electric power supply and temperature control system. The research results may constitute guidelines for the design and application of standards for assessing the effectiveness of thermoelectric refrigerators.