Refrigeration Technology

In the context of stringent reliability and safety requirements in food production, stable operation of refrigeration systems is critical to product quality and uninterrupted manufacturing. This article presents an economic rationale for implementing an internal specialized staff training system aimed at reducing operational risks and improving the efficiency of refrigeration equipment operation. It is shown that specialized training—structured as a logical continuation of foundational education—reduces new employee onboarding time, decreases staff turnover, and lowers the frequency of equipment failures. Financial analysis indicates a return on investment of 43.7% with a payback period of just 1.4 years. The findings confirm that systematic personnel training should be viewed not as an operational expense but as a strategic investment in production resilience and competitiveness.

Background: Nitric oxide NO is used in medicine and as an additive in artificial atmospheres for boxes and incubators. It is mainly obtained by a plasma method, passing a gas discharge through air or a mixture of nitrogen and oxygen. The use of effective conditions for obtaining this gas will optimize the design of the device and increase the NO yield while maintaining the input power.

Aim: Evaluation and analysis of the influence of pulse repetition frequency on the amount of nitrogen monoxide produced in the discharge.

Methods: To experimentally evaluate the effect of pulse repetition frequency on the change in the amount of NO obtained, an experiment was conducted for which a test bench was assembled based on a plasma chemical reactor (PCR) and an OPTIMA 7 gas analyzer, which was used to record NO concentration values corresponding to a given pulse repetition frequency.

Results: As a result of the work carried out, the existence of regions in which the concentrations of nitrogen mono- and dioxide change according to a nonlinear law was demonstrated, presumably associated with the resonant characteristics of the PCR parts, including the dependence of the reactive and active resistance on the PCR design.

Conclusion: The analysis and calculations revealed that the evaporation surface area directly impacts the amount of evaporated boil-off gas and the power consumption of the boil-off gas compressor. The data obtained suggest the possibility of creating low-power life support systems, such as incubators, as well as closed-loop therapeutic treatment rooms based on a device for generating NO.

Technical audits of refrigeration equipment in food processing facilities enable the identification of hidden faults and help prevent emergency shutdowns that can result in significant operational and financial losses. This review presents a real-world case involving the diagnosis of a screw compressor in a chiller using R404A refrigerant, which exhibited abnormally high discharge temperature while an identical unit in a parallel circuit operated normally. A comprehensive diagnostic approach—including thermal imaging, real-time monitoring of electrical and thermodynamic parameters, vibration analysis, and testing for non-condensable gases—revealed that the root cause was improper configuration of the automatic control system: insufficient compressor off-time, lack of refrigerant pump-down before shutdown, and excessive start cycles per hour. These factors led not only to elevated suction superheat and motor overload but likely also to mechanical wear of the compressor components. The review emphasizes the necessity of an integrated technical audit methodology combining instrumental measurements with a thorough understanding of refrigeration control logic to detect and prevent such operational failures at an early stage.