In this study, a new cooling system for a room is investigated. The system cools a ceiling surface with ceiling-adhering air jets and expects to improve the radiant field within the room. The cooling system intends to reduce draft risk by curbing the cooled air currents' direct invasion into the dwelling space. We investigate in detail, the characteristics of the thermal environment of a single cooled room with this system. In this report, we investigate the blown air-jets' adhesion to the ceiling surface, using a one-half scaled model of a living room assumed to be a living room of an ordinary residence. We also present the results of analysis of the radiant field in the room based on the results of measuring wall-surface temperature distribution. We thus obtained results demonstrating the effectiveness of cooling systems using ceiling-adhering air jets. Specifically, when the blown air-jets exhibit adhesion to the ceiling, (1) radiant heat exchange within the room is promoted and a more uniform, milder indoor thermal environment is realized, and (2) the blown air jets sufficiently rise in temperature and decelerate by the time they reach the dwelling space and draft risk due to blown air-currents in the dwelling space is reduced. In Part 2, we investigate the indoor thermal environment formed by this cooling system, using CFD-based analysis of room air-conditioning efficiency and ventilation efficiency.

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In designing air conditioning equipment, it is important to grasp in advance whether the design exhibit equipment's abilities or not. So, we take up rooms and duct system for air conditioning equipment and to execute an air conditioning simulation. This paper refers to make clear various characteristics of control, at the same time to execute air conditioning simulation. Parameters of the subject includes the heat characteristics of rooms, air temperature and humidity, special quality of control and wind environment. We employed two models for the air conditioning simulation. One is a lecture room in a university, and the other is a clean room. As a result, we recognized the efficiency of VAV in controlling room temperature and pressure, securing fresh air, and conserving heat source energy.

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In order to evaluate the performance of mechanical ventilation system, which is installed in a long office space of the east-west orientation, the ventilation efficiency at various points are measured. The ventilation system intakes outdoor air from the east side and exhausts indoor air to the west side. The measurements provide evidence that (1) the actual ventilation performance of investigated office space is almost the same as designed, (2) the difference between the step-up and the decay methods is very small, (3) the ages of air obtained by the step-up method using SF_6 are somewhat greater than those by the decay method using CO_2.

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The development of high efficiency refrigeration cycle is important for energy saving in order to inhibit global warming. The refrigeration cycle with two-phase ejector is very useful to decrease compressor force and raise the coefficient of performance of the refrigeration cycle. In order to make clear the characteristics of the two-phase ejector refrigeration cycle, the cycle simulation is developed in this study. The following results were obtained by using this simulation. The increment of the condenser pressure and decrement of the sub-cool temperature are effective for raising the coefficient of performance of the refrigeration cycle. The energy efficiency of the two-phase ejector used in this experiment was approximately 12%. The efficiency is expected to be increased by the improvement of the mixing characteristics of the ejector and the nozzle efficiency.

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Improvement and uniformalization of melting from a vertical heated plate imbedded in a paraffin (n-octadecane) was experimentally studied by using fins. The shapes of melting front was determined photographically for (1) without fins, (2) solid-type fins and (3) perforated fins and the melting rate was compared with each other. The size of fins is short at the upper part of a vertical heated plate and is long at the lower part of the plate considering on the effect of natural convection. The melting is enhanced for the perforated fins whose holes contact to the heated plate. Solid-type fins have an extended surface effect, but natural convection is depressed with melting. In the case of perforated fins, melted liquid moves through the holes. Therefore, the effect is remarkable near the lower section of the vertical heated plate.

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The Old Yodo River flowing through Osaka city is one of the typical urban rivers in Japan. The flow condition and water quality of the river were investigated in detail in the previous paper on the basis of the data by actual surveys in winter and in summer. In the present paper, an unsteady two-layer model of fresh and salt water, which is based on the findings about the flow condition in the previous paper, is proposed to predict the flow condition and water temperature of the river. It is verified that the model is available to the flow analysis of the Old Yodo River because the calculation results about the flow condition agree well with the observed results. Moreover, the water temperature rise caused by cooling water discharged from a district heating and cooling plant was predicted using the model and maximum available river water for cooling water was decided in accordance with a certain water temperature standard. It is found that the maximum available river water becomes much less in the tidal region where the adverse current occurs according to the tide than in the upper stream region where the river water flows always down in the same direction.

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The purpose of this paper is to develop the synthetic evaluation method of assessing district heating and cooling system. Firstly in this paper, the authors selected 10 indices as representative indicator of district heating and cooling system as follows: 1) Consumption of energy resources. 2) Utilization efficiency of energy supply infrastructure. 3) Economy. 4) Efficiency of space use. 5) Impact on global atmospheric environment. 6) Global warming. 7) Impact on local environment in DHC area. 8) Impact on landscape. 9) Safety and disaster-prevention. 10) Comfort and convenience of occupant. Secondly, values for each indicator are calculated for seven types of district heating and cooling system under a certain condition. The differences among these systems and the influence of calculation method are discussed.

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In this study, a heat exchanger was directly inserted into a well 40m deep and 267mm in diameter and employed in an experiment designed to use groundwater flow to gain an understanding of the characteristics of heat dissipation for cooling into the ground. At the same time, a method was proposed for analyzing heat transfer between the well water and the ground, and its suitability was clarified through comparisons of measured and calculated values. The results can be summarized as follows: 1) The results of water pumping experiments conducted on two wells indicated that groundwater flowed at the rate of 0.181m/day in the study area. 2) The heat dissipation per unit of time was greatest for the 12-hour heat transfer with sunlight blocked (about 1.08kW); per unit length of the heat exchanger, it was 0.108kW. 3) The core flow rate within the well was calculated to be 0.552cm/day, about 3 times higher than it would have been had here been no well. This corresponds quite closely with the results of previous studies. 4) The dissipated heat was 16.38MJ/day. The heat transfer for the ground was calculated to be 14.25MJ/day, for a differential of 13%. 5) The measured and calculated values of heat dissipation roughly corresponded with one another, and the same values for well-water temperature showed excellent correspondence.

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The purposes of this paper are to propose an optimal operational planning method for an energy supply system including ice bank, and to investigate the effect of the temperature of supply water and air on the long-term economics of the total system. The operational strategy of constituent equipment is determined together with thermal storage level of ice bank so as to minimize the daily operational cost by considering characteristics in ice bank during ice making and thawing. This optimization problem is formulated as a large-scale nonlinear programming one with a number of unknown variables. In order to solve the problem, an algorithm is proposed on the basis of feasible direction one. A numerical study is carried out for an energy supply system including ice bank to be installed into a commercial building in order to ascertain the effectiveness of the proposed method. Through the parametric study with respect to both capacity of ice bank and the temperature of supply water and air, the economic property has been evaluated, and the following main results have been obtained here. 1) The proposed method enables easy and rational determination of the operational strategy for an energy supply system including ice bank. 2) It has been made clear how the temperature of supply water and air influences on the long-term economics of the total system. There exists the optimal temperature minimizing the annual total cost. 3) It has been ascertained that installation of appropriate capacity of ice bank reduce the annual total cost.

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