As earth's environmental problem have become a global issue, reducing carbon dioxide emissions from both public and industry has been watched with keen interest. Therefore, several attempts have already put into practice in several fields to cope with this issue. Here, buildings consume a large amount of energy. Especially, as building services consume most of it and its carbon dioxide emissions during durable time hold about 20% on LCCO_2, we should take measures to control them appropriately to prevent wasting energy. Generally speaking, using energy consumption unit in different application per floor is effective to find energy wasting and improve its operation status. Then, to achieve this purpose as mentioned before, we have developed building energy telemetry system and installed it in our 58 office buildings to monitor electrical energy consumption in different application. We have carried out investigation aiming to clear energy consumption units in small office buildings with multi-split type air conditioning system. In this report, results of this survey on our two small office buildings, which have about 75 electrical power monitoring points such as lighting, plugs for OA instruments and power including air-conditioning systems, are shown. It is found that annual electrical consumption unit per total floor area except for special appliances use, which is categorized peculiar load of the electric power company, is around 1,550MJ/m^2 and there is room for further energy savings.

View full abstract

The purpose of the study is to establish a database on building equipment design and building simulations for the Chinese locations. In Part 1, data with three-hour intervals were interpolated using the Integrated Surface Hourly database. The design outdoor temperature for 360 Chinese locations was calculated based on the observational weather data during the period of 1995 to 2005. The design temperature for heating and cooling was approximated by hourly change ratio so that the design temperature could be simplified. Finally, problems with the ongoing design temperature were pointes out comparing to the design data suggested in this study.

View full abstract

This research introduces an electrolysis process into an activated sludge processor, electrolyzes turning on electricity a DC current in an aeration tank, and rotating an iron electrode, and makes applicable to examination the system "electrolysis activated sludge method is called henceforth" which separates and carries out water disposal with a sedimentation tank. In the experiment, it experimented paying attention to the fundamental matter of this system, 1st-step experiment, the alternation of the current value to the inside of activated sludge predicted that processing was influenced, the experiment was advanced, and the optimal amount of turning on electricity was examined. 2nd-step experiment, about the influence on the treated water by the existence of an electrode rotation, control of maintenance was also taken into consideration and examination was advanced experimentally. The optimal iron consistency, rotational existence, and the operational condition of the current value which turns on electricity were proposed from the experimental result.

View full abstract

The heat loss of room air under air conditioning is dominated by convective heat transfer on wall surfaces. Correct understanding of the thermal environment distribution in computational fluid dynamics (CFD) analysis therefore requires prediction of convective heat transfer on wall surfaces with excellent accuracy. It is necessary that a turbulence model and boundary conditions be chosen for CFD analysis that provide accurate understanding of a convective heat transfer behavior and laminarization phenomena of turbulence. The standard k-ε model for a fully disordered flow field cannot provide a highly accurate solution in viscous regions or regions where near-wall turbulence laminarizes. Accordingly, many low-Re turbulence models that can express convective heat transfer from laminar to turbulence exactly have been proposed; examples of their application to practical use computations are increasingly reported. However, because analytic accuracy in analysis using low-Re turbulence models might depend on grid division of a viscous sub layer region, verification of the accuracy has persisted as a problem. Detailed results of natural convection field experiment for CFD accuracy verification by Tian et al demonstrated the feasibility and validity of analysis using CFD for this issue. This study is intended to elucidate the analytic accuracy of CFD analysis of a natural convection field. Using various turbulence models, CFD analysis of the natural convection field experiment of Tian et al. was conducted. Comparison of analysis results with results of experiments verified that a low-Re k-εmodel and the SGS damping LES can reproduce natural convection heat transfer with sufficient accuracy.

View full abstract