Refrigeration and Air Conditioning
Corrosion damage of equipment is one of the main reasons for the accelerated failure of the machines and apparatuses of refrigeration equipment. Among the various types of corrosion is the most dangerous MKK – intergranular corrosion that develops at the grain boundaries of materials. This type of corrosion affects all corrosion resistant alloy steels, including austenitic stainless steel grade. The work investigated the resistance of steel containing 18% chromium, 10-13% Nickel in conditions simulating the operating conditions of the equipment exposed during the operation of the processing or repair, in particular, welding warm UPS in the long run. Testing the propensity of a material to the ICC was carried out according to the method of AMU (GOST 6052-75) austenitizing samples after provoking heating in the temperature range 670 – 1070К during the time from 0.5 to 100 h Were performed studies of mechanical properties of steel in authentisierung state and after provoking a tendency to ICC warm-UPS, the methods of emission spectral microscopy and auger spectroscopy were studied the surface of fracture samples, provided data on the redistribution of major alloying and impurity elements in the grain boundaries of the steel after provoking heating and the role of the grain boundary of the formed CE-gregate in the change of resistance of steel against exposure to corrosive environments. The emergence and development of non-equilibrium segregation of phosphorus in the course of a provoking tendency to warmed up ICC-world war II causes a decrease in the cohesion of grain boundaries and, conse-quently, leads to a decrease in corrosion resistance and embrittlement of the material.
Before the transportation of liquefied natural gas through a pipeline it is cooled. For this purpose a method of evacuating the vapour space above the liquid is frequently using. This work compares the energy costs of issuance of the cooled LNG pressurized by squeezing his own steam and with the use of the liquid pump. Also energy costs for LNG precooling with liquid nitrogen are showed. It is shown that the lowest power consumption of these three schemes shows an embodiment of cooling by evacuation with subsequent liquid injection pump.
In recent years, heat pump devices are widely applied to the decision of different tasks of heating. In some cases, according to technical, economic and thermodynamic indicators a HP has advantages over other types of heating : heat boiler stations, electrical heaters, centralized supply of heat energy from CHP. It is believed, that a field of HP applications is limited by southern or central regions where temperature values of low potential sources are sufficiently high. Nowadays there is evidence of HP widespread use in Scandinavian countries and Northern Europe where climate is harsh. There is some experience of the HP use in Russia. However, a question about efficiency evaluation remains open. HP is a new departure in heat power industry although its operating principles are well known. In this paper the attempt is made to use some methodology of exegetical analysis for thermodynamic effectiveness estimation of a heat pump cycle in heating of a cottage with the use of low latent heat of BALTIC Sea.
General cryotherapy is a physiotherapy procedure based on intensive hypothermia of the covering tissues of the human body. The purpose of the General cryotherapy is to stimulate the cold threshold receptors of the skin by reducing the surface temperature of the body to the subterminmal temperature –2 °C. In this case, the signals of the skin receptors reach maximum intensity and cause positive shifts in the broad spectrum in the human body. Development of technology for the supercooling of body cryogenic gaseous medium is complicated by ethical requirements. The only method of research in this area is the method of mathematical modeling. Given the complexity of the structure of the object of exposure, the construction of a complete mathematical model seems to be an impossible task. Taking into account the specifics of the simulated process, a simplified mathematical analogue of the cover tissues of the human body can be used for research in the field of General cryotherapeutic impact technology. The efficiency of the mathematical model of the "shell" of the human body constructed using the passive boundary of the simulated object is shown.