The purpose of this paper is to investigate the relationship among the ventilation, heat sink of the earth and the thermal environment in a subway. In the first place of this paper, the measurement of air temperature and humidity ratio in the subway was performed under the condition that mechanical ventilation was being operated and non-operated. According to the result, it was clear that the effect of mechanical ventilation is considerably large. Secondly, numerical simulation of the thermal environment in the subway was performed. Accuracy of the simulation result was examined by using the measurement results. From the simulation results, heat sink of the earth was proved to have an important role of lowering the air temperature in the daytime in summer.

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A new type heat storage system was proposed, in which the heat storage medium is concentrated by using the latent heat generated during both condensation and evaporation processes of the compression type heat pump refrigerant, while chilled water is cooled through the heat storage medium dilution process. A full scale apparatus, having a capacity of 70kW, was constructed and used to demonstrate the feasibility of the proposed system. In a series of experiments on heat storage and release properties, the performances of several heat exchangers was evaluated regarding efficiency of operation. Experimental results showed that sufficient cooling heat was generated during the heat storage medium dilution process under a peak load during daytime, while heat was stored during the medium concentration process using the heat pump at night. The heat storage capacity of 560000kJ/m^3 was obtained. The limiting steps were clarified by measuring the total heat transfer coefficients of several heat exchangers, then methods to improve the performance were discussed.

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It is required to measure their local values and their anisotropy of thermal conductivities for functionally gradient materials simultaneously. We have been treated the former technique accomplished under steady state. And we hope to establish the above mentioned technique by improving the former technique. In this study, we attempt to decrease the number of observed points at first as a clue to simplify the measurement. Before setting to an experimental measurement, the effects of both the location and the number of observed points on the results obtained in a numerical analysis were investigated by means of Kalman filter-finite element method using two dimensional steady state model with a heat source.

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In this paper, in order to investigate the applicability of 3-dimensional numerical calculation method considering radiant heat transfer effect for the model equivalent to that used in the experiment, a series of numerical simulation were conducted with SIMPLE algorism and were compared with the experimental results. As the results, the total heat loss through walls, the average temperature in occupied zone, the air temperature and velocity distribution and the distribution of vertical temperature of the experiment could be simulated exactly. It was confirmed that this calculation method is applicable and useful for this kind of models. Moreover, as the application of that, for general residential rooms, the fundamental characteristics of factors related to the thermal environment such as room scale, wall structure, supply air temperature and air flow rate for energy saving, average temperature in occupied zone, air temperature and velocity distribution were investigated. The fundamental characteristics by numerical calculation were hardly different from results of the experiment basically. However, with the increase of room scale and the decrease of thermal insulation of walls, the superiority of the method of horizontal air supply at the bottom of fancoil unit was shown in comparing with that of vertical air supply at the top.

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A conventional ice-on-coil system has refrigerant or brine coils inside a storage tank filled with water, which requires agitation of the water to promote uniform ice making and melting. In this paper a new type of ice-on-coil system is proposed, which consists of a water tank, coils located above the tank, an upper water distributor, and a circulating water pump. Water is distributed uniformly over the coils and it forms falling thin films. Ice is formed on the outside of the coils through recirculation of tank water. Ice is melted in contact with return water from a secondary (load-side) loop, while the water is chilled again and drops into the tank. In order to estimate roughly performance characteristics of the new system and to compare them with those of the conventional system, numerical analyses are done based on simple models. The estimated characteristics of the new system are as follows: 1) Filled water volume can be reduced and consequently the rates increase of water cooling and subsequent ice making. 2) Leaving water temperature is kept stably at 0℃ even at high heat loads, as long as ice remains. 3) The coefficient of performance is improved in compressor aided operation. 4) Agitators are not employed and hence the additional power and heat gain due to agitation are eliminated. 5) Ice quantity can be detected more accurately by measuring water level.

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The present study deals with the change of wettedness under the constant average skin temperature observed when the subject is clothed in the hot environments and the effect of its characteristics on the line of equal average skin temperature. In order to obtain the characteristics of the change of wettedness under the constant average skin temperature 36℃, the experiments were carried out using two young male subjects in a climate chamber. The tests were conducted on sitting-resting subject dressed in summer clothing of 0.6Clo. The environments prepared for the experiments were such that the average skin temperature be equal, the combinations of air temperature T_a and relative humidity R.H. be (T_a=36〜38℃,R.H.=30〜40%),(T_a=34〜36℃,R.H.=50〜60%) and (T_α=32〜34℃,R.H.=70〜80%). From the basic measurements of both environmental parameters and human physiological responses, the authors found the wettedness value changeable even if the average skin temperature was constant. Moreover, the following results were obtained under the conditions of resting-sitting, of summer clothing worn, of still air movement and of the constant average skin temperature 36℃; 1. there is a positive correlation between wettedness and the environmental vapor pressure. 2. there is a negative correlation between wettedness and the air temperature. 3. there is a positive correlation between the evaporative heat loss from the skin surface and the air temperature. 4. there is a negative correlation between the heat loss and the vapor pressure. 5. there is a negative correlation between wettedness and the evaporative heat loss. 6. both the maximum and minimum values of wettedness correspond to the average skin temperature. Considering the afore-mentioned results, the locus of the equal average skin temperature does not form a straight line, but forms a curved line on the psychrometric chart.

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An experimental study of free convection heat transfer along a vertical partition between a hot room and a cold room in a house has been carried out using a one fifth scale model filled with Freon gas R114. The results of the visualization of free convective flow along the partition, the vertical temperature distributions of the fluid and the partition, the grade of temperature stratification of the fluid, and the vertical distributions of heat flux across the partition and local heat transfer coefficient on the partition are presented and compared with those for air, which were obtained from the same experimental apparatus. In both cases of R114 and air, the vertical temperature distribution of the fluid and the partition are symmetric with respect to the central horizontal line of the apparatus, and are nearly linear except the regions near the floor and the ceiling. In the case of air the flow pattern along the partition is laminar in the whole region, while in the case of R114 it is turbulent from the upstream end. The grade of temperature stratification of R114 is larger than that of air. The relation between the local Nusselt number and Rayleigh number is correlated as follows: Nu_x=0.35Ra_x^<0.3> for 10^5<Ra_x<1.5×10^7 (R114 and air) 0.067 Ra_x^<0.4> for 1.5×10^7≦Ra_x<8×10^9 (R114) The average Nusselt number can be correlated by the equation for a rectangular enclosure if the fluid temperatures at the 1/5 height from the upstream end and wall temperture at mid-height of partition are taken as respective representative ones. It is also demonstrated that the temperature destributions of the fluid and the partition and the heat flux across the partition can be predicted by using the present results when the temperatures of the heated and cooled walls are given.

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In the analysis of flow in piping networks, dividing and combining losses at branches are usually ignored as being minor compared to the friction losses in pipes. But the losses at branches are not minor in many industrial piping systems. In the previous reports, Part 1, 2 and 3, the effect of these losses to the flow distributions and overall loss coefficients were quantitatively cleared in the case of basic T-type pipe flow. In this report, some new method is presented by which the energy losses at branches in the flow analysis of piping networks can be dealt with, based upon the linear theory method. The summary of the method proposed is as follows: 1) A newly defined matrix C is introduced which represents linearized dividing and combining losses at branches. 2) By adding this C to a part of the matrix A related to linearized losses in linear theory method, it is possible to consider the losses at branches in a piping network collectively. 3) The matrix C can be constructed automatically in the program by properly assigned input data. Experiments on the flow distributions for a specially constructed experimental piping system were also carried out and the validity of the proposed method has been verified experimentally.

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The flow pattern of a miter-tee with the branching angle of 90° and with roundness at the lateral entrance was studied for laminar flow. The areal ratio m was chosen to be equal to 1.0, 1.5 and 2.0 and the dimensionless roundness R was chosen to be equal to 1.0 for each m. Moreover, R was chosen to be equal to 0.5 for m of 1.0. The Reynolds number Re_<1h> was taken to be less than or equal to 200. The ratio of lateral discharge to total discharge Q_3^*/Q_1^* was changed from 0.0 to 1.0 at 0.1 intervals. The conclusions can be summarized as follows: 1) To investigate the flow mechanism in a miter-tee of the laminar flow, the Navier-Stokes equations were solved numerically by the finite difference relaxation method when Re_<1h> covered a range between 1 and 200. The influence of such parameter as m, R, Re_<1h> and Q_3^*/Q_1^* on the flow separation caused in the lateral conduit and the stagnation point was investigated. The effect of the flow dividing in the lateral conduit is larger than that in the main conduit. Its degree in the lateral conduit grows when the separation occurs. Generally, the degree of the separation caused in the lateral conduit with roundness at the lateral entrance is smaller than that without roundness there when Q_3^*/Q_1^* is 0.5 and Re_<1h> is greater than or equal to 70. But the former is larger than the latter when Re_<1h> is 70 and Q_3^*/Q_1^* is small. The mechanism of the flow separation is discussed physically. Moreover, 2) the influence of Re_<1h>, Q_3^*/Q_1^*, m and R on the stagnation point is studied. The stagnation point is located on the lateral wall of the middle point of the main conduit independent of Re_<1h>, m and R when Q_3^*/Q_1^* is 0.5. But the stagnation point varies with the values of m and R when Re_<1h> is 70 and Q_3^*/Q_1^* is changed. 3) The flow field in the real pipe junction with rectangular cross section was studied experimentally by the flow visualization technique when Re_<1h> covered a range between 5 and 200. The flow is two-dimensional at Re_<1h>≦40 but three-dimensional with secondary flow at Re_<1h>≧70. The flow adjacent to the center-line plane is always observed to be two-dimensional. The influence of m, R, Re_<1h> and Q_3^*/Q_1^* on the flow separation caused in the lateral conduit and the stagnation point was investigated. 4) The results obtained by the numerical analysis and experiment coincide fairly well. Both results coincide quantitatively well when Re_<1h> is small or when Re_<1h> is large but Q_3^*/Q_1^* is small.

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In many real cogeneration systems, the waste heat exhausted from main drivers is sometimes not effectively utilized by waste heat refrigerators. It arises often in case of parallel running of ordinary gas-fired refrigerator and waste heat refrigerator, because the former shares much cooling thermal load and the latter cannot share the prior load. Consequently, even if there exist plenty of cooling thermal load and available waste heat, the latter is sometimes thrown away wastefully. In order to solve this problem, it is necessary to install an adequate load sharing control scheme investigated particularly for cogeneration's waste heat refrigerator. In this paper, according to the following steps, the above-mentioned problem is investigated and some useful results have been obtained: 1) The refrigerator's load sharing phenomenon is analyzed for several systems of different refrigerator's connection and control types; i.e., the maximum capacity of prior load sharing of waste heat refrigerator and the temperature of chilling water are compared with. 2) The physical condition necessary to improve positive utilization of waste heat is analysed from refrigerators' hardware standpoint. 3) Some main analytical results are proved through the experimental study on a real existing cogeneration system.

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