The paper presents the results of the overview of literature data on the presence of calculation dependences that allow determining average heat transfer coefficients along the surface and local heat transfer coefficients at refrigerants boiling inside tubes. The calculation dependences to determine heat transfer coefficients at boiling inside tubes for different conditions of flow are cited. The calculations carried out and the comparison of calculated and experimental data resulted in the choice of the formulae for calculation of a heat transfer coefficient when a singlephase liquid flows inside tubes as well as for calculation of a heat transfer coefficient in the zone of a developed bubble boiling of a refrigerant in a large volume. The formulae allow calculating thermal characteristics of evaporators at refrigerants boiling inside tubes more accurately. The use of calculation dependences cited gives the possibility to reduce the time for searching and actualization of formulae that suit more for calculation of thermal characteristics of evaporators at refrigerants boiling inside tubes.

The relevance of usage and revealing of new mixed refrigerants is described. A comparison of vapor compression refrigeration cycle working on new mixed refrigerants such as R448А, R449А, R450А and R513А is examined. A comparison methodology is given and the analysis of obtained results is shown. A comparison of these refrigerants in terms of ecological safety is given. A way of vapor compression heat pump cycle improvement is described in order to enhance its effectiveness by using more efficient refrigerant and also by modifying the unit construction. Cycle modelling in software package Aspen HYSYS is performed and software selection is substantiated. Major graphical dependencies and cycle parameters are given. Zeotropic refrigerants usage features are presented

The paper examines an economic appropriateness of using systems of a heat pump hot water supply under Russian economic conditions. Also cost effectiveness of hot water generation using a boiling plant on natural gas was specified. A comparative analysis of technologies of hot water supply systems examined is given. It was defined in a calculated manner that full production costs of hot water generation (US dol./year) are equal for both technologies. A cost price of 1 gram calorie of heat for heating water using a heat pump is a little lower than using a boiling plant. But the payback time of a heat pump hot water supply system under Russian conditions is longer. It is shown that the system of hot water supply using a boiling plant provides a quick repayment and so is economically an effective trend.

A Stirling engine was invented 200 years ago. Its author was ahead of its time. Only in the 50s of the last century its satisfactorily working samples were manufactured by Phillips. A cryogenic gas machine (CGM) working on the reverse Stirling cycle was developed and experimentally investigated at the same time. Key indicators of CGM with discontinuous and harmonic character of piston movement are described in the paper. It is shown that in a real Stirling machine with losses from internal and external irreversibility there can be achieved optimal cooling temperature at which the degree of thermodynamic perfection becomes the maximum. Results of arrangement of various CGMs, including Stirling, working with the unsteady flow of the working fluid are considered. Place of the Stirling cryogenic machine family made in the considered systematization, which uses only the general thermodynamic features, is determined.

The process of freezing influences deeply the product elements formation and their dispersibility at ice cream production. The shape and dimension of ice cream structural elements that are ice crystals and air bubbles depend greatly on freezing speed and mechanical impact on the product. The freezing speed increases significantly at the product freezing in a liquid nitrogen medium. The paper cites the results of experimental studies with respect to the estimation of the impact of the process of the quick freezing of liquids in a liquid nitrogen medium on dispersibility of structural elements and organoleptic indices of ice cream. Also a comparative estimation of qualitative indices of ice cream produced at mixtures freezing in the liquid nitrogen medium and in the freezer was carried out. It was defined that the freezing of the mixture for ice cream led to the formation of small ice crystals that couldn’t be felt by sense organs. The possibility to produce frozen desserts in the liquid nitrogen medium as well as using mixtures for fullcream ice without food additives - stabilizers of structure and consistence was justified.