Speaker
Description
Topic “Environmental Protection Systems”
Abstract. The work is devoted to the research of the process of measuring substances that negatively affect on the ozone amount in the atmosphere. The analysis of chemical-climatic models of the atmosphere used in environmental monitoring is carried out. Mathematical methods for calculating the effect of freons on the ozone amount is considered. The detecting method of freons are chosen on the basis of refrigerant characteristics.
Key words: freon, climatic changes, gas analyzer, raman spectroscopy, refrigerating agents, ozone layer.
Introduction. Atmosphere monitoring is one of the key tasks to ensure a comfortable living environment. Leaks of refrigerants from air conditioning systems, fire extinguishing systems, refrigeration equipment with the release of freons into the atmosphere are a potential hazard. The most dangerous are Freon-12, Freon-22 and other refrigerants that affect on the amount of ozone in atmosphere [1]. These refrigerants are currently being replaced by multicomponent mixtures, which still contain HFCs, but in significantly small proportions in relation to single-component freons. The issue of detecting these low concentrations of ozone depleting substances is relevant in the production of such refrigerants and in the analysis of counterfeit products.
The work purpose is research of the features of measuring ozone depleting substances at ecological monitoring. There are several tasks which helps to achieve the goal:
1. Describe refrigerants that are hazardous if released into the atmosphere.
2. Analyze interaction mathematical models of refrigerants with the atmosphere.
3. Choose the method of freon measuring for controlling the leaks into the atmosphere.
Body. According to standard ISO 817-2014 “Refrigerants. Designation system”, there are several groups of freons which representing the greatest danger when released into the atmosphere [2]. These include representatives from the groups of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), etc. The distinctive feature of these substances is a long-life span in the atmosphere, calculated from several years to several decades. One example is HFC Freon 23, which will decay in the atmosphere within 270 years. These substances are dangerous, since when interacting with radiation in the ultraviolet region, they release atoms of bromine, fluorine, chlorine, which, in turn, upon contact, destroy the ozone layer.
The analysis of chemical- climate models of the atmosphere on the formation and decay of ozone was carried out. On the basis of these the process of creation and decay of ozone was considered.
When reviewing mathematical models of the interaction of refrigerants and ozone, it was concluded that it is advisable to detect freon leaks into the atmosphere.
Based on GOST R ISO 17584-2015 "Refrigerants properties", an analysis of the characteristics of freons was carried out. Due to the complex composition of the analyzed substances of HFCs, it was proposed to use the method of Raman spectroscopy.
The distinctive feature of Raman spectroscopy is the observation of scattered radiation from the sample, as a result of which this method is not sensitive to absorption bands. Thereafter, the study of the detected anti-Stokes lines provides accurate information about the analyzed component, since the measurements are carried out with scattered light.
Conclusion. The description of ozone depleting substances, which are the objects of research, was carried out. The properties of freons, which affect on ozone amount in the atmosphere, were investigated. Based on a mathematical model of the interaction of a refrigerant with the atmosphere, it was proposed to use the Raman spectroscopy method for detecting low concentrations of refrigerants and for component analysis of HFC mixtures.
The work have done with the support of project №620159 «Development and research of the principles of building a digital freon analyzer».
Sources:
1. Tsvetkov O.B., Baranenko A.V., Laptev YU.A., Sapozhnikov S.Z., Khovalyg D.M., Pyatakov G.L. Ozonobezopasnyye khladagenty/ Scientific journal of NUY ITMO. Series “Kholodilnaya tekhnika i konditsionirovaniye", № 3, 2014–pp.98-111.
2. ISO 817-2014 Refrigerants. Designation system.
| Position of speaker | Graduate student |
|---|---|
| Affiliation of speaker | ITMO University |
| Publication | IOP Conference Series: Earth and Environmental Science |
