Methods of calculation of energy losses of the refrigerator when opening its doors

Abstract

The problem of energy supply and the problem of energy efficiency of energy consumers are global problems. In the modern world, scientists pay much attention to the tasks of creating new and improving traditional sources of electricity. The tasks of increasing the energy efficiency of electricity consumers remain relevant in the global economy. One of the relatively capacious energy consumers is the Park of refrigerators, household and commercial purposes, which are also being improved in order to increase their energy efficiency. Modernization and improvement of household and commercial refrigerators include the task of designing and using more efficient refrigerators. Energy consumption of compression refrigerators, along with other operational factors, depends on the processes of heat exchange and mass transfer of air from internal chambers to the ambient air. When the doors of the refrigerator chambers are opened, the cooled air in the chambers is replaced with the warmer air of the environment. This process causes the cost of operation of the refrigeration machine and characterizes its energy consumption. In order to minimize this power consumption, knowledge of the process of cool air outflow of their open refrigerator chambers is required. Currently, this process is poorly understood. The article presents an approach to the description of the process of motion of the cooled air from the refrigerator chamber, the main assumptions necessary for the construction of a mathematical model of this process are given, and a method for calculating the heat in the refrigerator chambers associated with the replacement of the cooled air with the ambient air inside the chambers is proposed. The method is based on the laws of gas dynamics, supplemented by some experimental studies. In particular, the well — known Navier-Stokes equation is used as the initial basis. This equation supplemented by the continuity equation of the air flow and other functional dependencies. As a result of mathematical transformations and arguments about the physics of the mass transfer process, finite equations are obtained, which allow describing both the performance of the cooled air flow and the amount of heat introduced into the chambers by external warm air. Mathematical dependences are developed for calculation of parameters of motion of a stream of the cooled air and heat inflows, thus the temperature of ambient air and temperature in chambers of the refrigerator are considered. The results of the research will be useful in the design of new refrigerating machines with reduced energy consumption.