The premixed combustion under the fuel-lean condition is effective in reducing the NO_x quantity. Furthermore, a multi-port type premix burner can distribute the premixed fuel and air to each small port and shorten the flame, and the heat load is increased easily. In this kind of combustion systems, supplying homogeneous mixture is essential for the equalization and the reduction of the combustion temperature all the burner surface over. With the previous methods that estimate the degree of mixing, it is impossible to get the detailed and quantitative information about the flowing mixture simultaneously. In this paper, a convenient method to estimate the degree of mixing on the gaseous mixture is proposed. Dry-ice mist, that is fed into the mixer instead of the gaseous fuel, is visualized with the He-Ne Laser Light Sheet as the fuel distribution in the mixture. The density of the mist in the mixture is measured by an image of the scattering light intensity taken with a TV camera and the degree of mixing is calculated. The multiple scattering characteristics on the mist are investigated on the experiment with the homogeneous mixture. The following knowledge, that enables to get the proportional image to the density distribution, is composed based on these characteristics. 1) The quantity of the fed mist should be kept as lean as possible, to reject the weakening of the incident light. 2) The forward scattering light should be detected, to strengthen the image intensity. 3) The non-linear relation between the image intensity and the density, that is made by the spatial error of the scattering angle and by the geometrical arrangement of the optical devices, should be compensated under the multiple scattering characteristics. As applications of this method, this paper shows some results of the tests on a mixer that is composed of a multi-blade fan and a sub mixing chamber. The mist is visualized on the outlet of the mixer, which is 60mm by 80mm. The mixer without the sub mixing chamber mixes the fuel to the air partially and the arrangement of the fuel supply nozzle influences the density distribution. On the other hand, the sub mixing chamber improves the mixing characteristics of the mixer with the extension of the path and the enforcement of mixing with the impeller. At the end, this method can be successfully applied to the measurement of the mixing characteristics on the wide burner surface, which is 260mm by 80mm.

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A simulation model for ice storage tanks using supercooled water was introduced from scale model experiments. Two inlet types were examined, that are shower inlets splayed from nozzle and a pipe inlet from upper part of the tank wall. Various combinations of temperature and flow rate were set to analyze influences of input heat or Archimedes number. Since tiny particles of ice made from supercooled water floated upper region of the tank, the flow of input water tended to make bypass between the ice mass and tank wall to the outlet. The proportion of the bypass flow depended upon the type of inlet, flow rate, and Archimedes number. For the shower inlets, low input temperatures or small input heat made the output temperature lower than 4℃. Comparing same input temperature and input heat conditions, high flow rate made the output temperature lower. For the pipe inlet, temperature stratifications were observed for large Archimedes numbers. Volumetric heat transfer coefficient that indicates heat transfer per unit volume was introduced to calculate heat transfer between ice and water. The mixing model for temperature stratified storage tank was applied so that the influence of temperature stratification could be accounted. Calculations showed good agreement with experimental results. The volumetric heat transfer coefficient and the depth of complete mixing region were the parameters of this model. Correlations between two parameters and input conditions were obtained from experimental data. Therefore, the prediction of storage tank performance can be achieved.

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The study was dealt with the effects of substrate composition in synthetic wastewater to growth of filamentous organisms. This paper described on the following items. 1) The synthetic substrate was observed on the degeneration. As the result, some of fatty acids were apparently formed in the synthetic wastewater. 2) The experiment was practiced by the specified apparatus (rotary cylinder type), using about 10 kinds of the wastewaters. As the result, the water soluble fatty acid would be caused unusual growth of filamentous organisms. 3) Compared filamentous organisms with flocculating bacteria in biodegradability for the substrate in No.1 water, it was higher in filamentous organisms than in flocculating one; the biodegradation was made rapid progress in about 72 hours at 20℃. 4) Two fatty acids (non- and water soluble) were served as substrates. The results were as follows. (1) Myristic acid had no unusual growth of filamentous organisms. (2) Propionic acid caused biological bulking in activated sludge in about 10 days.

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It has been well known that the heat pump system of air heat source can not be efficiently applied in cold regions, because the evaporator in heating mode is very easy to be frosted and COP will be low. Instead of air heat source, the ground can be used as a heat source in cold regions. The experiments of evaporating heat transfer were made in a vertical long-length U-tube for heat extraction in the direct-expansion ground coupled heat pump system. The experiments were carried out using R22 for pressures of 0.42 to 0.64MPa and mass flow rates of 90 to 300kg/m^2・s. The test tube is a smooth copper tube with 8.0mm I.D. and 9.5mm O.D. and the whole length of 12m. The temperatures of the flow fluid and test tube surface, local heat transfer coefficients and pressure drop were measured. The effects of the various parameters on the heat transfer coefficient, such as the evaporating pressure and heat flux, were discussed. The results of local heat transfer coefficients were compared with those given by other investigators, and a dimensionless correlation of the heat transfer coefficients was suggested, which was in good agreement with the present experimental data.

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Periodic heat transfer with adsorption and desorption process in an element of the matrix of the rotary total heat exchanger is studied numerically and experimentally. The outlet temperature and humidity variations of the exhaust air and the intake air are predicted respectivily for summer time conditions. Mean values of these results are agree well with the measured ones. Effectiveness of temperature, humidity and enthalpy are also obtained for different flow rates and it is shown that the effectiveness of humidity and enthalpy increase with decreasing the flow rate, but that of temperature does not increase and rather decreases at the relative low flow rates.

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This is a basic study on utilizing the urban waste heat of low level temperature to district heating and cooling systems of Sapporo City. Firstly, we estimated the energy demand used for the domestic sector of Sapporo and its spacial distribution, both which are to be fundamental materials for the study. The total energy demand and total heat demand per annual were 40×10^3TJ and 30×10^3TJ, respectively. We also evaluated the existing urban waste heat and its distribution in the city, and the total amounts to 11×10^3TJ per annual. As for the low level temperature waste heat, through the evaluation, it has been seen that because of low quality the directutilization such as snow melting is to be planned in the first place in the case of Sapporo. A method of assessment is required for the low level temperature waste heat. Then, some performance indices have been produced. They show advantages of the heat pump utilizing the low level waste heat as heat source, against the air source heat pump, in view of energy conservation. Being examined on characteristics and applied to the existing sewage waste heat, these indices have been confirmed to have very usefulness. Lastly, we have indicated a procedure to judge whether to utilize low level waste heat through a simulation on an area where a district heating is assumed possible, to which the indices are actually applied.

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The load in the water supply system of buildings occurs in using fixtures and the variation of flow quantities is remarkable, and the characteristics of load are different according to a kind of fixture. It is necessary for designing a plumbing system to get hold of dynamic characteristics of load and to analyze the behavior of the current in this system. In this paper, the authors constructed a model piping-system with two branch pipes, and investigated and analyzed the relations between the characteristics of flush valves for experiments and that of numerical simulations. Then, the dynamic characteristics of the simultaneous load in water supply was evaluated by information entropy.

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The purpose of this study is to estimate maintenance policies for automatic control facilities. So the quantitative evaluation of various decision making factors including qualitative ones is enabled by using Analytic Hierarchy Process (AHP). This epoch-making method is a kind of the operation research, mainly used for some decision making. This paper investigates many maintenance policies and decision makings when it checks the periodical inspection with questionnaires on service engineers. The main result obtained is; These decision makings estimated many technical factors by service engineers, but these maintenance decision making practiced by many economic factors or user's point of view. This result will feed back to planners as well as service engineers.

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This paper discusses an air-cooling-type cooling apparatus which cools a room having high heat generation throughout the year. Also, it discusses control methods in low outdoor air temperatures. One aspect of cooling apparatus as for computer rooms or telecommunication equipment rooms is year-round cooling. Therefore, a new control method which allows the cooling apparatus to operate efficiently in low outdoor air temperatures has been required. If the cooling apparatus operates as if the outdoor air temperature is high when in reality it is low, the quality of heat exchange in the condenser increases and condensing pressure decreases. As a result, the evaporator either freezes or excessively dehumidifies the room. In the conventional apparatus, a condensing pressure regulator is located at a merging point of the bypass and a path via the condenser to eliminate the above problems. However, the performance of a cooling apparatus using this method in low outdoor air temperatures is nearly equal to that in high outdoor air temperatures. Unfortunately, since a high condensing pressure results in increased power usage by the compressor, this method is uneconomical. The cooling apparatus, which is operated by a new control method, employs a condensing pressure control valve which can set a desired pressure and an expansion valve having a capacity larger than a conventional valve. By using the new control method, the cooling apparatus operates economically when the outdoor air temperature is low. This paper discusses formulation of optimization problem and modeling of a cooling apparatus in order to operate the cooling apparatus efficiently in low outdoor air temperatures. At first, to make the cooling apparatus efficient is formulated as a nonlinear constrained optimization problem of coefficient of performance (COP). After that, a nonlinear model of cooling apparatus is proposed to investigate the problem. Moreover, under several conditions of outdoor air temperature, the electric power used by the compressor is simulated for two operation variables, namely expansion valve opening and condensing pressure control valve opening. Simulated results are showed as contour line graphs of COP to the two variables. In the graphs, optimal states and their characteristics are illustrated.

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A coupled simulation of convective and radiative heat transport is very useful to predict thermal environment in an air-conditioned room since both convective and radiative heat transfer have important roles for computing the thermal environment in a room. In the previous paper, the coupled simulation which is using the convective heat transfer coefficient, α_c, for convective heat transfer simulation and is using Gebhart's absorption factor method for radiative heat transfer between solid walls, were examined. In this paper, the coupled simulation within the complicated geometry is dealt with. For calculating shape factors in the room with complicated geometry, the Monte Carlo Method is introduced. The method has essentially inaccuracy of its calculation due to the statistical errors in itself. The correction method against the inaccuracy is conceived and its validity is confirmed by some example simulations. The new coupled simulation method including the modified Monte Carlo Method is applied to the thermal environmental simulation with an furnished room with complex geometry. The results of simulation are compared with those of the experiment and it is proved that the new method is useful for those application problem.

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The standard weather data in Osaka (new version), Nara, Kanazawa, and Wajima for ten years from 1980 to 1989 are developed. These data consist of several outdoor weather effects: air temperature, absolute humidity, direct radiation, diffuse radiation, cloud cover, wind direction, and wind velocity. Using the standard weather data, yearly variation of daily average, average daily variation for each month and histograms of daily average are calcurated. The above statistical properties are compared between the six data: these are the four data above, the old data in Osaka (1960-1969) and the data in Toyama. The comparison between the new data in Osaka and the old one shows that grobal radiation of the new one is more than that of the old one, it is remarkable in summer, the difference of the monthly summation between the two is about 130 [MJ/m^2 month] in July. In addition, the maximum grobal radiation of the old data is less than 24 [MJ/m^2・day] and that of the new one and the data in Nara is 30 [MJ/m^2・day]. Temperature of the data in Nara is about 2[℃] lower than that in Osaka all year round, and that in Kanazawa is 1-3[℃] higher than that in Wajima or Toyama.

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The temperature selective heat storage tank which was proposed in previous papers prevents supplied fluid of arbitrary temperature to mix with other temperature layers in the thermally stratified stage. This feature is superior to that of conventional heat storage system, but still not enough for a true temperature selective heat storage tank. In this paper, the principles of the extraction of destined temperature layer are shown and a test model to corroborate the simultaneous extraction of discharged two temperature layers is proposed. Two extracting sub-tanks having several dampers with actuators are installed in the main tank. Sensing surrounding temperature in the main tank, dampers are opened and closed by actuators which are driven by shape memory alloy springs. By sucking from the extracting sub-tank, heat storage medium in destined temperature layer flows through opened dampers and is extracted from the main tank. Four layers of thermal stratification (10, 17, 40 and 48 degree Celsius) were formed in the main tank (1000mm width, 1500mm height and 400mm length). Intermediate two layers of water were extracted separately from each extracting sub-tanks by supplying hot and cold water from the top and the bottom of the main tank. Measurements of temperature distributions and visualization of extracting processes were performed. In the presence of temperature gradient between two dampers, limiting flow rates through a damper were measured by changing temperature distributions. In order to explain experimental results, limiting extraction model were proposed. Fairly good agreements were obtained between experimental and predicted results of limiting flow rates through a damper. Finally, by applying proposed limiting extraction model, the procedure to design the extracting subtank and damper actuators are shown.

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Energy management is a broader system integration technology than conventional energy saving technology. It also emphasizes efficient operation of energy systems. In part 1, we introduced this technology; explained the detailed method of constructing the best mixed system in practical case studies; proved that the combination of the heat storage system using midnight power service and the gas co-generation system with the joint use of electricity/gas meets the requirements of both energy conservation and economic efficiency. In this part, we analyze the practical operation data of 1993 to prove that the best mixed system was best in practice. Additionally we refer to studies on heat storage tanks, and discuss the verification of CO_2 and NO_x content from the standpoint of environmental protection.

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This study describes an estimate of the surface temperature at a vertical ground pipe considering the influence of the edges of a pipe and the ground surface to clarify the characteristics for the vertical ground pipe system. At first we verified that the limit of Fourier Number to calculate the surface temperature by line source was over 10. This was the result to compare the temperature at the radius of the cylinder formed by the line heat source with one by the cylinder heat source. Secondly, To estimate the surface temperature at a vertical ground pipe, the vertical temperature distribution and the average temperature at the imaginary surface of a pipe was calculated by the finite line source in the semi-finite solid. The solutions and figures to obtain the average temperature were shown and the relations between the average temperature and the pipe length, the radius, the values of soil character and time were indicated. At last we proposed the approximate method to calculate the average temperature by using the concept of the equivalent radius that shows the same temperature at the center of the pipe length as the average temperature. The equivalent radius is given by multiplying the radius by the coefficient of correction. The coefficient of correction changes by the form of input of the heat source. Its value is 1.57 under the steady-state condition, 1.0 for periodic input, if pipe length is more than 30 meters, and varies between 1.0 and 1.57 for step function.

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In recent years, the dynamic simulation on HVAC system has become more important for the control of indoor environment and energy conservation. For giving a minute description of control process in HVAC system, it is recommended to simulate the total system including the thermal dynamic characteristics of the elements and subsystems. This paper presents a simulation method that can be used for study on HVAC process dynamics and control tuning by the state transition method in which the time step can be freely selected. In this paper, a constant air volume and single duct system is chosen as the subject of this study. The simulation method presented in this paper gives a simple approach to modeling the control process of an indoor air temperature and the simultaneous control process of the temperature and the humidity in a typical room of the office buildings. As a result of these two kinds of simulations, various characteristics of the indoor air temperature, humidity, comfort and energy consumption in these different control processes are clarified.

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In recent years, energy consumption for the domestic sector has increased with improvement of the standard of living. The radical increase of the maximum hourly demand of electricity is threatening the generating capacity of electric utilities. On the other hand, city-gas utilities have the problem of seasonal imbalance of demand: peak in winter and off-peak in summer. A thermal energy storage system is widely recognized as a demand-side management technology for shifting the electrical cooling demand from peaktime periods to off-peak nighttime. This system enables users to reduce their electricity costs by reducing peak demand and taking advantage of off-peak usage rates. City-gas companies are also promoting cooling by gas fired chiller-heaters, offering an incentive in usage rates. This paper reports that a hybrid energy source system, using an electrically driven, screw heat-pump chiller-heater and a gas fired absorption chiller-heater with thermally stratified chilled/hot water storage, adopted for a middle scale office building, is effective in demand shifting and cost savings. In this building, the thermal storage tank is located at the basement, between the basement floor slab and the structural ribbed mat. The tank, utilizing the space of the substructure, consists of seven concrete vessels which are interconnected by sleeves through the grid of beams. The water level of the tank accordingly becomes very shallow, and the water depth is only 1.7 meter. For this experimental office building, the temperature stratified thermal storage system with distributor/diffusers is adopted to achieve high efficiency, although it becomes less efficient as the tank becomes shallower because the blended zone becomes a larger fraction of the height of the tank. Recently, this substructural space is often used for grey water reservoir because many localities are short of water. Well-stratified storage tanks have high efficiencies and can considerably reduce the volume requirement compared with conventional systems. The operating data of this hybrid system with the themal storage tank was collected for three years. The results of this study show that this system is effective for both users and energy utilities. This system enables not only users to reduce their energy costs, but utilities to reduce peaks and fill off-peak valleys, thereby improving various management problems.

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