This paper constitutes Part 3 in the series of studies on hybrid utilization of renewable energy and a fuel cell for a residential energy system. First, field experiments on the electric power and domestic hot water supply system using both solar energy and the fuel cell were carried out. The primary energy reduction rate to a conventional system reached 46.6%. Second, the hybrid system on the electric power and domestic hot water supply was analyzed for the residential energy system both in Sapporo and Tokyo. It was clarified that the optimum capacity of the fuel cell consisted for approximately 1kW in Sapporo.

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The purpose of this study is to develop a new calculating method for water supply demands in restaurants. The authors have advanced the development of calculating method for the time series loads, such as daily, hourly and instantaneous loads by using a computer. In these study, the method that applies a unit model as the water consumption of one kitchen was proposed. By using this method, it is possible to prospect the loads of water consumption in restaurants. In this paper, the measurements of water consumption were carried out in three university cafeterias with the aim of applying the method to the restaurant which supplies a large quantity of foods, such as cafeteria and canteen. In each cafeteria, the volumes and temperatures of cold and hot water were measured in every one- minute in each season; autumn, winter, spring and summer. These data were measured by dividing the kitchen into two systems, such as a cooking zone and a washing zone. From the results of measurements, the daily, hourly and instantaneous loads in the kitchen and each system were shown. Also, the relationships between daily water consumption and number of customers were analyzed. And, the calculating unit models of water usage in each system were set up. The time series loads in a university cafeteria were calculated by using the method that applied the Monte Carlo Simulation Technique. As the results of comparison between the calculated data and the measurement data, it was shown that the calculating method was effective in university cafeterias.

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Against the background of the recent trend towards air-conditioning on a personal basis, many studies are being undertaken regarding control of thermal comfort for individual office workers and assurance of the quality of inhaled air. As a result, various personal air-conditiong (PAC) systems have been proposed. This study proposes a PAC system that effectively improves the quality of inhaled air by supplying a large amount of clean air directly to the inhaled air region of the body. A PAC system with large supply openings is newly proposed for this purpose. Assuming a state of steady human inhalation, the effect of different supply opening sizes on inhaled air quality is studied in detail for the same airflow rate on the basis of computational fluid dynamics (CFD). Inhaled air quality is evaluated using passive-scalar analysis, which is applied to ventilation efficiencies in the inhaled air region of the room's occupant and the contribution ratios of gaseous pollutant generated in the room. In the case of PAC with small supply openings (high wind velocity), mixing of the supply air with the surrounding air is enhanced. But, in the case of PAC with large supply openings, mixing of the supply air with the surrounding air is small and ventilation is efficient as shown by the small values of the age and residual lifetime of air compared with the other cases. Also, the influence of pollutants emanating from furniture and wall surfaces in the room on the inhaled air is small. Furthermore, In this study, PAC system is suggested to decrease the risk of inhaling the ETS (Environment Tobacco Smoke) in the condition that smoking person and non-smoking person stay in same time in an office. The characteristics of the indoor environment are examined using CFD simulation, and the inhaled air quality of the person is investigated also. The PAC system is found to be more efficient than the usual all-air system for keeping passive smoker in good air quality in a case of staying with smoker. As results, the large supply opening PAC system removes the mainstream of smoked-air until about 82% and the sub-stream is reduced until about 90%.

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We propose a method for task area wide-covering personal air conditioning that prevents a human body in task area from being exposed to a largely irregular thermal environment, we have achieved the result in effectiveness to thermal comfort of the human body. However, this system is aiming at securing an excellent inhaled air quality, the examination concerning the inhaled air quality with wide-covering personal air-conditioning is not enough. In this report, we analyzed about inhaled air quality with wide-covering personal air-conditioning by the CFD analysis. When personal air-conditioning is used, the inhaled air quality becomes excellent compared with the case only of ambient air-conditioning. The fuel spray travel of the cooling air of wide-covering type is long, though an effective diameter of wide-covering type is larger than that of spot type. So the value of SVE3^* of wide-covering type is old. On the other hand, recently we use adsorption constriction materials and a desk-top absorbent to improve the air quality in the task region. In this report, we also analyzed the effect of the improvement of the inhaled air quality when we use personal air-conditioning together with the adsorption material is examined. The current of air properties greatly influence the inhaled air quality, and the use of the adsorption material that doesn't consider the ventilation route doesn't have the effect of the improvement on the inhaled air quality. An appropriate ventilation plan is necessary to secure an excellent inhaled air quality. And a remarkable difference was not seen in inhaled air quality of spot type and that of wide-covering type. Wide-covering type is better from the overall viewpoint because effectiveness to thermal comfort of this has already been confirmed. And it can maintain secure inhaled air quality when we use wide-covering type together with spot type.

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The electric power load changed for a short time is given to the fuel cell system for residences, and the heat response characteristics are analyzed. The heat exhaust of a fuel cell and a town gas reformer, the heat output and power consumption of heat pump, the amount of town gas consumed by the system, and the relation of the range of fluctuations of electric power load were investigated by numerical analysis. In numerical analysis, even if it gave change of electric power load to the system, the town gas amount of consumption of the system obtained the result which is not influenced. Therefore, when using the fuel cell for residences, it is not necessary to take into consideration change of short-time electric power loads. When design of operational planning of the fuel cell cogeneration system, it is using the average electric power load of sampling time width (for example, 1 hour), and enough high-precision analysis is possible.

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