Improving the Efficiency of Heat Power Generation from Household Drains

Abstract

Minimization of consumption by the buildings during exploitation of energy resources produced of non-renewable energy sources is the main objective of modern energy efficient construction. Currently, there are two principal solutions to this issue: the use of renewable energy sources (such as solar energy, geothermal energy, etc.) and optimization of secondary energy consumption. The paper considers one of the main approaches of secondary energy consumption, which is advisable to use in residential buildings, viz. the use of heat of household drains. Taking into account the fact that in modern energy-efficient buildings a significant amount of energy is still spent on hot water supply, one of the options for optimizing this process is the reuse of waste water heat as the initial source of heating of cold water supplied to the building. The design and technological solution of the heat exchanger, which will make the most efficient use of waste water heat for heating cold tap water possible, is proposed. A characteristic feature of the heat exchanger is the providing a screw movement of waste water along the internal standpipe. At the same time, cold water moves evenly along its outer contour, gradually being heated up from household drains. The key problem of the considered design solution is the correct choice of the appropriate slope of the screw surface, which will ensure the maximum transfer of heat to cold water and at the same time provide a quality drain, eliminating the possibility of clogging and stagnation of small particles. In order to solve this problem an assessment of the existing theoretical and practical approaches to the provision of water flow in technological pipelines which allows determining the optimal value of the slope of the surface has been fulfilled.