| Abstract [eng] |
District heating in Lithuania is supplied to 57 % users. Water treatment systems are widely installed in boiler plants where either fossil fuel or biofuel is used to generate the heating energy. These systems are used to keep the heating and energy supply systems more effective and prolong its lifetime. In any case, the water and energy resources are not always used effectively. Object of analysis – water treatment systems in boiler house. The first one is treating the surface water for supply to heating network, the second one is treating water from central network which is used to feed the steam boiler. Aim of the paper – to analyze and evaluate the potential and possibilities of water and energy resources used to prepare it in boiler plants either to expand its environmental efficiency. Master thesis tasks: 1. To perform the analysis of water quality and treatment types used in boiler house. 2. To analyze the effective ways of water recourses use in boiler plant. 3. To identify environmental problems of chosen objects. 4. To present the effective methods of water and renewable energy recourses usage according scientific articles and practice. 5. To evaluate environmental and economical value of suggested proposals. 6. To perform evaluation of systems life cycle assessment. The work consists of following parts: literature analysis of effective water resources usage, methodology of investigation, description and solutions of the environmental issues of investigated objects, evaluation of life cycle assessment, work results, conclusions and list of literature. According the analysis of effective water resources use the most efficient ways to save water and energy is water recycle and integration of renewable energy. For the system, where treated water is used for supply to heating network, the solar collector system which benefits to heat the surface water up to 10° (expenditures of electric energy are reduced by 35,4 % (EI=0,31 kWh/m3)) is integrated alongside with recycle system (quantity of sewage is reduced by 70,2 % (EI=0,06 m3/m3)). In the system where treated water is used to feed the steam boiler the photovoltaic energy power plants installed. It generates the energy which fully fulfills the water treatment system demands (271 480 kWh/year). After performing the assessment of water treatment systems life cycle assessment the results showed that sewage water recycle and integration of renewable energy sources would considerably reduce the systems impact to the environment. |
