Keywords: desalination installations, nuclear power stations, thermal schemes, thermodynamic processes, nuclear desalination
Thermodynamics of a desalination system at nuclear power stations
Nuclear power engineering is developing steadily in industrial countries. This is caused by features of using nuclear fuel and high environmental safety of nuclear power stations. At the same time, the thermodynamic efficiency of nuclear power stations is lower than indices of thermal power stations operating on gas, coal or oil fuel. This efficiency does not usually exceed 30–35%. Hence more than 60% of the energy of nuclear fuel being used escapes into the environment through turbine condensers at nuclear power stations. Cogeneration turbines that reduce heat loss by 20–30% are used at thermal power stations for efficiency upgrading. However, cogeneration schemes have not found wide utility at nuclear power stations due to safety conditions. Thus, it is possible to use, in addition, a major part of nuclear fuel energy for desalination at nuclear power stations located on the coast. In this case, some main problems are solved: production of fresh water consumed by nuclear power station for technological purposes and sold to external consumers; upgrading of effectiveness of using nuclear fuel including the cost of steady operation of nuclear power stations at high loads; reduction of non-productive thermal pollutants from nuclear power stations into the environment. It is required to provide maximum upgrading of power station heat efficiency and high capacity of distillers when connecting desalination installations to the thermal scheme of nuclear power stations. The use of energy of the heat carrier's low-temperature flows being emitted by turbine condensers into the environment is of particular value. In this case, different thermodynamic analysis methods are used for the justification of optimal engineering solutions In the article under consideration some results of research of thermodynamics of cycles of nuclear power stations where thermal schemes includes different types of thermal desalination installations are given. From the analysis of thermodynamic processes carried out at nuclear power stations, recommendations related to improvement of desalination installations' thermal schemes providing power system efficiency upgrading have been obtained.