In this paper, from the viewpoint of contamination control, a clean room with locally air-balanced supply-exhaust ventilation system installed at ceiling is studied. Flow and diffusion fields in this room are analyzed by both flow visualization and measurement. The results obtained from model experiments of this system are compared with those of conventional flow type clean room with exhaust openings at the wall. The flowfields of the former are characterized by the inflow jet and the rising streams around it, which are almost the same with those of the latter. The combination of one jet and the rising streams around it forms a "flow unit". The total flowfields are regarded as the combination of these flow units. In the total flowfield, we can allot each exhaust opening to the corresponding flow unit so as to make it in the condition of closed airflow within each flow unit. This situation is mainly possible by arranging exhaust opening at the ceiling. In this flowfield contaminant diffusion in the room is almost confined to only one flow unit. It is confirmed by the model experiment that the locally closed circuit ventilation system arranging supply and exhaust openings at ceiling is useful method for contamination control.

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This paper describes the prediction method of radiant environment in a room, in which the radiation interaction between human bodies and their surroundings is focused on. An arbitral complicated configuration in a three dimensional enclosure with human bodies, window and furniture in the room can be applied for this prediction method. A unique space index and another surface index are introduced to specify the geometry of solid body or surface in the room. In order to introduce the zone method, total exchange areas are calculated by the transformation from direct interchange areas which can be obtained by the Monte Carlo method. Energy balance equations associated with thermal radiation, convection, wall conduction and air ventilation are formulated at total number of divided areas. These non-linear equations can be solved by the combination of Newton-Raphson and Gauss-Seidel methods. A thermal human body model with some parameters of skin temperature and clothing is proposed to simulate its heat release and to predict a local thermal sensation around the body. Thermal radiant environments in a meeting room with floor heating panel are analyzed by the prediction method and checked in the case of sitting human bodies. Radiant asymmetry effects may be derived from the different irradiation and evaluated in terms of the direction and the position of this human body model.

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This report describes the concept of the minimum demand for water from the sanitary point of view, and introduces the necessity of this study, definition and basic concept of the minimum demand for water, meaning and application of estimating the minimum demand for water, kind of water usage and research theme, collection of data through literature survey, selection of the items for examinations, survey with questionair and estimation of minimum demand for water. In this paper, the level of water usage are divided in four steps, like in emergency, urgency, ordinary uses and rich uses. The paper also refer to the water saving and effective use of water. If one is able to clear the limit volume of water considering the level to keep one's life and household sanitation in an emergency and urgency (which is so called minimum demand for water), design data for daily load can be estimated rationally by multiplying it with the rate of margin. As the result of these estimations, the accuracy of design data are upgraded, and it should be possible to approach the limit designing.

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This report describes the experimental study on the minimum demand for water by means of bacteriological approach in the case of washing hands. The minimum demand for water has been defined as the level required to keep one's life and household sanitation. By considering the personal differences like the surface condition of hands, and the habit of washing hands like as its frequency, way of washing and so on, the experiments were carried out for the different set of elements as follows: 1) kinds of faucet-extended shank bibb and spray faucet 2) type of washing-washing in running water and filled water 3) volume of water and flow rate 4) use or no use of soap 5) duration of washing hands As the results of experiments, the most effective way of washing hands, establishment of the minimum requirement of water consumption, and basic data for estimating the minimum demand for water are presented in this report.

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Ventilating performance of the vertical exhaust duct installed in multi-story houses was analysed by model experiment and computer simulation. The pressure losses at the flow junctions in the vertical duct were investigated by the model experiment. The pressure distributions along the vertical duct in three different multi-story houses of 5, 15 and 25 stories were calculated by the computer simulation. The results are as follows: 1) The pressure losses at the flow junctions in the vertical duct were expressed by the approximate equations with two ratios of the air velocity and sectional area in the vertcial duct to those values in the branch duct. 2) The pressure loss of the converging flow at the junction through the vertical duct was positive with tee junction, but that with elbow-type junction was negative. This means that the elbow-type junction makes the pressure in the duct increase upward, and the reverse flow from the vertical duct to the apartments possibly occurs in the upper stories. Therefore, the tee junction should be used in order to prevent such reverse flow. 3) It is possible to keep the pressure in the vertical duct at constant by controlling the rotational speed of the exhaust fan mounted at the top of the vertical duct.

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Concerning the spray flash evaporation occurring in a superheated liquid jet ejected from a tubular nozzle into a low-pressure vapor zone, effects of liquid temperature, liquid flow rate, superheat, nozzle diameter, and electrolytic current for the supply of bubble nuclei on the efficiency of evaporation were experimentally investigated for water as a working liquid. From the results, it was realized artificial nucleation enhances spray flash evaporation, thereby reducing the non-equilibrium loss, even in the cases of low liquid temperatures, small superheats, and large nozzle diameters. Consequently, the spray flash evaporation process can be applied to energy-saving systems such as heat pump systems utilizing various sources of waste heat, and the Rankine cycle solar cooling system.

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In recent years, many types of cogeneration plants have been installed into a number of industries and commercial buildings. It is reported that the total efficiency of energy utilization becomes very high by installing this cogeneration plant compared with the conventional heat and power supply plants. However, to achieve this high energy utilization, it is fundamentally necessary and important to operate the plant rationally and intelligently. In this step, there exists many alternative operational ways to satisfy energy demand required; e.g., it is possible to supply the heat for cooling by driving the electric or gas refrigerator, the gas engineor electric-driven heat pump, or the single effect refrigerator. Therefore, it is a difficult task for the planner to determine the plant's operational policy rationally by the conventional trial and error method. In addition, the supply-demand relationship between electric power and heat has a very close and complex connection. These facts cause the difficulty in the determination of the plant's operational policy. As the determination of this operational policy has a considerable influence on the economics of the plant, an optimal operational method has been proposed here. In this optimization method, the plant's operational policy is determined optimally so as to minimize the fuel cost for each hourly energy demand pattern. In the mathematical formulation of the optimization problem, it is necessary to take account of the on/off condition of each equipment. Here, by adopting the zero-one integer and continuous variables which indicate respectively on/off status and operational level of each equipment, the optimal plant's operational problem has been formulated as a mixed-integer linear programming one. The branch and bound method has been adopted here to solve this optimization problem. For the purpose of ascertaining the validity and effectiveness of this optimal operational method proposed here, a numerical study has been carried out for a cogeneration plant including gas engine generators and gas engine-driven heat pumps based on the real existing data. Through this numerical study, it has been ascertained that the optimal plant's operational method proposed here is a useful tool to determine rationally the operational policy of the cogeneration plant compared with the conventional trial and error method.

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The purposes of this paper are to propose an optimal operational planning method for a cogeneration plant including a heat storage tank, and to investigate the effect of heat storage on the total plant. For a diesel engine cogeneration plant, an optimal planning method is first presented by which the operational policy of constituent equipment is determined together with the charging history of the heat storage tank so as to minimize the daily operational cost. In order to solve this optimization problem efficiently, an algorithm is developed by combining the dynamic programming method with the mixed-integer linear programming one. Lastly, a case study is carried out for a cogeneration plant to be installed in a hotel to ascertain the effectiveness of the method. Through the study, the effect of heat storage on the total plant has been investigated from the viewpoint of the daily operational policy and the long-term economy, and the following main results have been obtained: 1) The proposed method enables easy and rational determination of the operational policy for the cogeneration plant with the heat storage tank. 2) The optimal operational policy adopts the daily pattern that the charging and discharging are repeated rather frequently so as not to increase the heat loss from the heat storage tank. 3) The installation of the heat storage tank and the adoption of the optimal operational policy reduce the daily and annual operational costs of the total plant. 4) It has been made clear how the volume of the heat storage tank influences the long-term economy of the total plant. There exists the optimal volume of the heat storage tank minimizing the annual total cost, which depends on both fuel price and capital cost of the heat storage tank. Though this paper has dealt with the restricted case study, the proposed optimal planning method has the flexibility with which it applies to the investigation into other cases.

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The exact similarity law for free convection currents is based on numerical identity of the Grashof numbers between a model and a prototype. It is well known, however, that the exact similarity law is not practical when a small model is used because heat quantity supplied to the model have to be greater 100 times than the prototype and the characteristic temperature have to be greater 1000 times if 1/10 model is used. In place of the exact similarity law, Shoda and Tsuchiya proposed a practical similarity law including an approximate similarity law which had been proposed by Maeda et al. According to the similarity law of Shoda and Tsuchiya, contraction ratios of temperature and velocity are related to those of dimension and heat quantity as follows: n_θ=n_<Qh>^<2/3>n_l^<-5/3> n_u=n_<Qh>^<-1/3>n_l^<-1/3> where n_θ, n_u, n_<Qh> and n_l are contractioll ratios of temperature, velocity, heat quantity and dimension, respectively and contraction ratio means the ratio of each quantity of a model to a prototype. However, more studies are necessary to confirm the validity of the above relations and to clarify the condition under which the relations hold. To investigate the above problems, the authors carried out systematic experiments with four different sizes of models for a simplified factory with a rectangular cross section. One of the models uses the water as a fluid. The velocities at the inlets set in the lower part of side walls were measured by smoke-wire method or hydrogen-bubble method. Temperature distributions in the models were measured with thermo-couples. Experiment conditions range from GrPr=3×10^3 to GrPr=1.6×10^8, where Gr is the Grashof number and Pr is the Prandtl number. As a result, it is clarified that the approximate similarity of Shoda and Tsuchiya is valid for turbulent free convection currents when GrPr is greater than 2×10^7.

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