Vol 106, No 7 (2017)

Now owing to manufacturing development and improvement air conditioners and air conditioning systems designed for production areas are of great importance at modern industrial enterprises. The power loading on these systems and air conditioners is continuously increasing, requirements are toughening as well but operation conditions become harder. The paper examines new designs of air conditioners and air conditioning systems to be used in production areas that have enhanced characteristics and are offered in patents and scientific and technical literature of developed countries. The main tendencies of development of air conditioners and air conditioning systems design are shown.

The author approach to calculation of the evaporation cooling process in the bank of tubes of apparatuses of refrigeration systems is presented. One of the particularities of the approach consists in the refuse of admission to be equal to the Lewis factor unit. It is established that the Lewis factor is a basic characteristic when analyzing the heat and mass exchange process; it allows explaining the character of the behavior of temperature and humid parameters of a waterair medium in the apparatus. The study carried out resulted in the offer to take into account the Lewis factor when calculating the coefficient of heat transfer from the wall outside towards the film of spraying water. Also it is offered to use the procedure based on taking into account enthalpies of humid air and spraying water in the apparatus as well as the information of the construction of the bank of tubes to define the quantity of heat transferred from a coolant (refrigerant) flowing in the coil of bank of tubes to a waterair mixture in the apparatus. The efficiency of organization of evaporation cooling processes in modern refrigeration systems was estimated.

The paper deals with the urgency of use and finding of new refrigerant mixtures that are, in particular, applied for heat pumps. To obtain high conversion efficiency an optimal composition of the CO2 /R32/R134a refrigerant mixture as regards thermodynamic and environmental characteristics was selected. Its main advantages as well as disadvantages were shown. Also the cycle of the heat pump was improved by a heat exchange apparatus adding; the last used the heat of rejected water after a consumer. The modeling of cycles using special program packages was carried out. The major graphic dependences and cycles parameters are presented. The improvements listed allowed obtaining the heat pumpwater heater conversion efficiency equal to 15,75. The main conditions to obtain such a high conversion efficiency of the plant are described.