Kutra D. The efficiency of heat pump schemes of energy supply of wood drying installations

The dissertation is devoted to the development of theoretical models and calculation methods needed to analyze the efficiency of heat pump installations in low-temperature convective drying of wood in batch cameras. Theoretical study of thermodynamic and energy efficiency of heat pump drying systems in the first and second period of drying for open utilization scheme, schemes with partial and full recycling and bypassing of heat pump were made. The impact of changes in ambient temperature, heat losses of drying chamber, the influence of thermal irreversibility in the heat pump, the size bypassing on thermodynamic efficiency of heat pump drying schemes were analyzed. The conditions of maximum thermodynamic efficiency heat pump drying systems were defined. The method of evaluation of specific energy consumption for evaporation of 1 kg of water for some of the most energy efficient systems were developed. The table data to quantify the energy efficiency of the considered schemes of heat pump dryer for the most common species of wood and their assortments were obtained, which can be used as estimated values for the design of heat pump dryers and operational evaluation of specific energy efficiency of drying process.