ANALYTICAL ASSESSMENT OF THE IMPACT OF DEPOSITS ON HEAT EXCHANGE SURFACES ON HEAT EXCHANGE EFFICIENCY

Abstract

Energy conservation is one of the priority directions of Ukraine's state policy in the energy sector. This course encompasses not only the implementation of innovative energy-efficient technologies but also the profound modernization of existing production capacities by replacing outdated technological schemes and equipment with the latest, highly efficient solutions. Particular attention is paid to the use of new generation plate heat exchangers (PHEs), which are distinguished by high thermotechnical, technological, and operational characteristics.

The high efficiency of these heat exchangers contributes to the optimization of energy consumption and the increase in the overall economic profitability of enterprises. The calculations of their thermal and hydraulic performance are based on the fundamental principles of hydrodynamics and heat transfer and are well-developed. This allows engineers to accurately select heat exchange surfaces according to the specified flow rates and temperatures of the heat transfer fluid. At the same time, operational experience shows that the theoretically calculated heat transfer area may require an increase of 20–200% due to the need to account for additional thermal resistance caused by the formation of fouling layers.

However, to date, the data on the thermal resistance of deposits are mainly of a recommendatory and fragmented nature, which complicates their practical application. They often do not take into account the specifics of heat exchanger designs and their operating conditions, and sometimes even contradict each other. This applies to both industrial heat transfer fluids and water – the most common one. Fouling of heat exchange surfaces significantly reduces the efficiency of PHEs in various industries, including transport, energy, technological processes, and the municipal sector. The formation of deposits on the heat exchange surface leads to an increase in electricity costs for pumping the heat transfer fluid, changes in the temperature regime, and, as a result, an increase in both capital and operating expenses. In critical cases, this can lead to the failure of the heat exchanger due to channel blockage.

Given the above, scientific research aimed at ensuring the long-term preservation of the design heat transfer characteristics is becoming particularly relevant. Their goal is to develop sound theoretical foundations and practical recommendations that will minimize the negative impact of fouling on the operation of heat exchangers, thereby contributing to increasing their reliability and efficiency.