THE INFLUENCE OF DIFFERENT FACTORS ON THE MAISOTSENKO CYCLE EFFECTIVENESS

Abstract

An important problem in the heat industry is the significant cost of energy resources for air conditioning. Therefore, energy-efficient refrigeration systems based on renewable energy sources and evaporative air cooling, as well as air-conditioning systems according to the Maisotsenko cycle using psychrometric energy of the environment are of great importance. This paper presents the results of experimental and numerical research of the influence of various factors on the efficiency of indirect evaporative heat and mass transfer apparatus on the M-cycle on the basis of a new unit cell. An experimental stand of a heat and mass transfer apparatus with vertically arranged plate channels was developed for experimental research. Experimental studies of heat and mass transfer in the new unit cell were conducted in a wide range of Reynolds numbers 200…1200, temperature 16… 30 °С, relative humidity 30… 50 %. The calculated study was performed using a modified ε-NTU method. Studies have shown that the thermodynamic efficiency of a wet bulb thermometer at a Reynolds number below 500 exceeded one. According to the results of computational studies, the influence of cell length and surface intensification of dry channels on thermodynamic efficiency was determined. Shown the effect of changes in thermodynamic efficiency in the range of 86…94 % increase in efficiency by 1 % leads to an increase in cell length by 7 %. The value of the enhancement factor increases with increasing air flow regime, so when the heat and mass transfer surface area increases by 50 % and the Reynolds number 200, the thermodynamic efficiency increases by 14 %, and with the Reynolds number 800 – by 28 %. The dependence of the thermodynamic efficiency of the cells at the dew point on the relative humidity of the inlet air have a maximum, which with increasing Reynolds number shifts toward larger values of relative humidity. Unlike traditional air conditioning devices, the M-cycle heat and mass exchanger does not use a steam compression cycle, so energy costs are spent only on the operation of the fan to pump air, which is a more environmentally friendly and energy efficient way of air conditioning.