In the previous report (part 3, published in 1996), the conditions to control excessive growth of filamentous bulking was proposed based on the experiments using synthetic waste water. In the above proposal, "Intermittent Inflow Process" was adopted with due consideration on substrate of synthetic waste water, BOD loading at the inflow point to the biological reactor, and inflow intervals. The intermittent inflow condition used for this experiments was to divide waste water into several batches (3 to 5 times per day) with BOD loading of waste water of 0.06〜0.2[g-BOD/g-MLSS・batch]. In this study, experiments were made with intermittent inflow process and continuous inflow process, using municipal sewage which was artificially conditioned to create uniform concentration. As a result, it was verified that the growth of filamentous bulking is controlled by the proposed intermittent inflow method.

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Control of HVAC systems has a lot of characteristics and difficulties such as multi-input/multi-output system, distributed parameter system, interference system, unsteady-state and dependency on flow fields. PID controllers are generally used in HVAC systems, but they need gain tuning task which results in waste of time. We describe in this report that we experimented temperature and humidity control using 3 layered Artificial Neural Networks (ANN) which have learning function. Back-propagation method is used when connecting loads of ANN are revised. We compare data of PID control without gain tuning to those of ANN+PID control and get a conclusion that ANN+PID control is effective. Furthermore, we compare ANN control without PID control to ANN+PID control. Both algorithms control room temperature and humidity simultaneously. RMS errors of those are almost equal, but the actuators of ANN control move more stably than those of ANN+PID control. In ANN control, we see difference of learning processes when learning factor ε and learning rate α are changed.

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In the first report, the airflow properties and thermal characteristics in the perimeter zone of an office window were evaluated by constructing an air barrier system that creates a push-pull air flow to remove heat entering through a window and enhances the adiabatic efficiency of the glass. This second report examines the heat extraction rate and shading effect of the window system. The air barrier system was evaluated by measurement of heat extraction rate and shading effect under a transfer thermal load attributable to a temperature difference inside and outside the window and a transmissive thermal load due to sunlight. The results confirmed that a shade attached inside the window can remove the transmissive thermal load in order to reduce the shading coefficient for sunlight. Thus, the efficacy of the air barrier system was confirmed.

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In designing stage of buildings, the ventilation rate of fresh out door air is mainly determined under the assumption of perfect mixing room air. The assumption is appropriate and useful when the room is mechanically ventilated and contaminant source in the room is almost evenly distributed like ordinal offices. However, this assumption is not appropriate when the contaminant is unevenly distributed or when the special care for occupancy region air quality is paid. To estimate local efficiency of ventilation and air-conditioned air distribution, three scales for measuring ventilation effectiveness in a room (SVE 4, 5, 6) are defined based on the CFD analysis of room air and added to the authors' evaluation system of SVEs (Scale for Ventilation Efficiency 1, 2, 3). SVE 4 indicates the contribution ratio of a supply opening to air at a point in a room. SVE 5 gives the contribution ratio of an exhaust opening to air to be exhaust at a point. SVE 6 indicates the residual lifetime of air at a point. These three scales, as well as previously defined SVEs, are evaluated from the distribution of contaminant concentration in a room. In order to confirm the usefulness of these three scales, the characteristics of ventilation effectiveness in two rooms with different ventilation system are analyzed.

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The significance of the assumption that on/off operation of air conditioning can be treated as a Markov Process was estimated stochastically on architectural heat transfer phenomenon with a series of numerical experiments. Transition probabilities of cooling to no-cooling state and the reverse were defined as functions of outdoor and indoor SET^*. Cooling heat loads of a single room model in a residential building were calculated in the numerical experiments based on Montecarlo simulation. The experimental results indicated the significant influence of stochastic on/off operation of the cooling system not only on seasonal but maximum cooling heat loads.

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This paper describes the results of experiments on a total of eight passive systems consisting of various combinations of the direct gain system, the Trombe wall, and a green house. The results of these experiments can be summarized as follows. 1) In the case of the direct gain system with a concrete floor, although the diurnal variations in room temperature were low, the daily range increased to 55℃ when the floor was insulated. The greater heat capacity of the Trombe wall plus slab had the function of keeping the room temperature more constant. 2) The overall heat transfer coefficient and heat capacity of the rooms complete with each system were calculated from the measurements by a least-squares method using the Householder transformation. Results demonstrate that this method better explains the experimental results than a well-known solution using a least-squares method based on a normal equation. 3) The heat collection efficiency of each system installed in a room was estimated from the overall heat transfer coefficient. Taking the heat collection efficiency of the direct gain system as 100%, that of other systems was estimated as follows: 42% for the direct gain system with the green house; 47% for Trombe wall (H=2.4m) plus slab; 50% for the Trombe wall (H=2.4m) plus slab and air circulation; 54% for the Trombe wall (H=1.6m) plus slab. 4) The calculated amount of heat absorbed into and released from each system nearly agreed with the measured values. The ratio of intensity of incident solar radiation to the amount of heat absorbed into each system was 37〜39% for the direct gain system, and 47〜53% for Trombe wall plus slab systems. 5) The room temperature was restrained by about 3℃ during the day and kept higher by about 4.5℃ at night by the Trombe wall (H=2.4m) plus slab.

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Using road heating systems for snow melting consumes a great deal of energy increasingly, and thus it is not desirable in the aspect of global environmental issues. Therefore we proposes a combination system of snow melting and solar water heating to improve the total energy efficiency. In this system, the heating coils for snow melting are utilized as solar water heater outside of the winter season. The solar water heating performance of this combination system is examined by the field experiment and the numerical simulation. The results are as follows. 1) The thermal energy collected by the coils embedded in the 20m^2 asphalt pavement was approximately 1000MJ for 71 days. 2) The numerical simulation corresponded to the results of measurements within 10% error except the day affected by rain. 3) The quantity of the circulation flow and the ability of the heat exchanger in this system don't affect the solar collecting performance excessively. 4) The temperature of the storage tank after supplying hot water, the installation area of coils and the weather condition affect the solar collecting performance respectably.

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In this paper, a method of numerical simulation is proposed for evaluating the behavior of indoor temperature and flow fields in detail. The result of temperature and airflow distributions in rooms is discussed from the view point of window sash modelling which affects the solar heat gain in a room. In the simulation, the sash of windows are simplified to calculate the solar heat gain in the room and the effect of simplification of sash on the simulation results are considered. A coupled simulation of CFD (Computational Fluid Dynamics), radiative heat transfer, solar heat absorption and heat conduction in walls is conducted for this purpose. It has been done on the basis of experimental data which was measured without air conditioning in an experimental atrium. As a result, the following conclusions are revealed; (1) the shielding ratio of sash in each glazing surface where solar radiation enters affects the solar heat gain in the room strongly, and the large amount of error rises in neglecting the sash modelling. (2) The more accurate the modelling conducted with this technique considering the shielding ratio of sash, the more accurate results obtained. (3) For practical use, reasonable results can be obtained by setting the overall transmittance and absorptivity of solar radiation in each glazing surface in response to the ratio of sash area to glass area.

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This report describes numerical and experimental investigations on the discharge characteristics of fixed beds for latent heat-storage by using cross-linked, form-stable polymer particles as the heat storage material (HSM) and ethylene glycol as the heat transfer fluid (HTF). In the numerical analysis, the effects of the type of HSM, the initial temperature in the fixed bed, the inlet temperature of HTF, the mass velocity of HTF, and the mass of HSM packed in the fixed bed (the height of the fixed bed) on the distributions of transient temperatures of HSM and HTF in the fixed bed and on the transient outlet temperature of HTF were calculated by using a finite-difference, implicit method with iteration. In this case, the HSM-to-HTF heat transfer coefficient in the fixed bed was evaluated according to the empirical formula which was recommended in the authors' previous report for fixed beds of form-stable polymer particles subjected to melt-freeze cycles. The relationship between the transient inlet and outlet temperatures of HTF was also revealed through the numerical analysis. In the experiment, the transient outlet temperature of HTF and the substantial ending time of latent heat discharge period were measured under various conditions. The experimental results were found to be in fair agreement with the numerical results, showing the validity of the present method of numerical analysis.

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This study describes the long-term measurement and numerical analyses of earth temperature profile under natural climatic conditions in order to make a fundamental data base for Underground Thermal Energy Storage (UTES). First of all, we have measured the earth temperature for about two years at the observing station, which was constructed in Sapporo in 1994. As a result, the temperature of a constant earth temperature layer was approximately 10.3℃. Next, we prepared a calculation program of earth temperature for a snowy region. The results of the calculated earth temperature and snow depth on this program mostly agreed to that measured at the observing station. Also, it was found that the calculation program can be used efficiently in other domestic regions.

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