Vol 107, No 12 (2018)

The paper shows that according to standard documents high investments are needed to create test benches for testing refrigeration centrifugal compressors at high power intensity. Also it is shown that the compressor testing using the heat exchange equipment with twophase refrigerant state in a thermodynamical cycle leads to increasing the period of testing and reducing the accuracy of obtaining results due the system lag. Two test methods are examined that provide reducing capital expenditure, working hours, expenditure of energy and increasing test results accuracy as well: the first method based on the similarity theory of compression processes supposes the test operation under modeling conditions, and it is intended for obtaining gasdynamic characteristics of the compressor; the second one using a test bench with refrigerant partial condensation provides a compressor test operation under natural conditions without using fullsize heat exchange apparatuses, and it is intended for confirming its working capacity. It is shown that the methods developed and realized in AO “VNIIKHOLODMASH” allow reducing significantly capital expenditure, working hours, expenditure of energy for test operation of refrigeration centrifugal compressors as well as reducing time to development and correcting makeready of new equipment.

The efficacy of influence of gammaradiation and further cold storage under modified atmosphere on the change of factors characterizing fruits quality keeping was examined. The quality keeping capacity of fruits irradiated by 1-3 kGy doses and stored under modified atmosphere (5-15 % СО2; 5-10 % О2) was studied. The retardation of the ripening processes of irradiated fruits was established. The possibility to reduce some postradiational changes was revealed; stabilization of fruits resistance to pathogens, keeping breath level, retardation of fruit ramolissement and tissue permeability etc. were observed. It was defined that the complex storage technology reduces losses and prolongs berries shelf life by 1,5-2 weeks, drupaceous fruits shelf life by 3-4 weeks; also it improves products microbiological safety.