Energy sustainable development through energy efficient heating devices and buildings
Energy devices and buildings are sustainable if, when they operate, they use sustainable (renewable and refuse) energy and generate nega-energy. This paper covers three research examples of this type of sustainability: (1) use of air-to-earth heat exchangers, (2) computer control of heating and cooling of the building (via heat pumps and heat-recovery devices), and (3) design control of energy consumption in a house.
Cooling energy evaluation for high-rise residential buildings in Hong Kong
Based on the design of a typical high-rise public housing block in Hong Kong, the dependence of space cooling loads of residential flats on the constructions of external walls and partitions, and the location of thermal insulation layer in the walls and partitions, was studied by detailed simulation. The results show that insulating the envelope and the partitions would be effective in reducing the yearly space cooling load, by up to 38%, but could either increase (by up to 19%) or reduce (by up to 16%) the peak cooling demand, depending on the number and positions of insulation layers in the walls. Reducing the thermal capacity of the envelope and partitions (e.g. by reducing their thickness) would lead to large increases in the peak cooling demand, by more than 60% in the extreme case.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.