The purpose of this study is to develop a method to investigate the reduction of energy consumption of the operation phase of a hospital using a simulation. In this study, the improvement of the operation of the heat source system and secondary system in winter were investigated using the simulation. In the hospital investigated in this study, air source heatpump, gas driven and steam driven absorption chillers, steam boiler, and water thermal storage tank are installed as heat sources for heating and domestic hot water supply. Exhaust hot water and steam from the electric generator (CGS exhaust hot water and exhaust steam hereafter) can also be utilized. Secondary system is divided into a four-pipe system and a two-pipe systems, in the latter, heating is supplied for 24 hours. For the two-pipe system, hot water is supplied from the water thermal storage tank, and the heat is stored by the air source heatpump and/or CGS exhaust hot water. Furthermore, CGS exhaust hot water can be supplied to the domestic hot water system with CGS exhaust steam and boiler. In this study, the optimal operation of the air source heatpump, CGS exhaust hot water, exhaust steam, steam boiler for the heating load of the two-pipe system, and the domestic hot water supply load are examined. For the secondary side, the energy saving effect of the transportation power by optimizing the temperature difference was examined. The examination was carried out for one week in February when the heating load was heavy, and in March, when it was relatively small. By simulation, it was shown that the conveying power can be reduced by optimizing the temperature difference in the secondary system. Further, it was found that the primary energy consumption can be reduced by changing the heat source of the thermal storage from the CGS exhaust hot water to nighttime operation of air source heatpump and the use where CGS exhaust hot water is supplied. It is expected that the energy consumption will be further reduced by changing the operation of the CGS corresponding to the operation improvement of the heat source system and the secondary side system. Therefore, the influence of changing the electric power load and the use of the CGS exhaust heat to control of the optimal operation of the generator was investigated in this study. It was found that it is possible to further reduce energy by the optimization of the control value of the CGS according to a load after the improvement of the operation of heat source system and secondary system.　

In this research, a method for estimating the heat addition in winter and the heat extraction in summer of a heat/cool trench is devised based on subterranean heat transfer numerical analysis. First, the numerical-analysis technique of subterranean heat transfer is applied to the calculation of the cross-sectional temperature distribution of a building and the circumference foundation, and the concrete skin temperature in a trench is found. Next, from the heat transfer between the trench surface and passing air, the air difference in temperature between the entrance-exits of a trench is predicted, and the heat addition quantity and the quantity of heat extracted during the period is calculated.

In this study, sample risk prediction training sheets (hereafter, risk prediction sheets) illustrated with work scenes that are quite common to construction sites are proposed to train onsite operators for improving their risk prediction ability, by letting them envisage and freely describe the potential hazards in the sheets. The supervisors and workers were trained in order to comprehend the degree of their risk prediction ability by occupation, experience and age. A total of 943 subjects from building contractors and their affiliates participated in this survey. The ratio of supervisors to workers was 1:1.3. The total number of risk prediction sheets filled by the subjects was 943: 81 sheets by inexperienced supervisors, 325 sheets by experienced supervisors and 537 sheets by workers. The results were analyzed by occupation, experience and age. The major findings from this survey are summarized below. (1)For the analysis by occupation, the experienced supervisors scored the highest on most sheets followed by the workers and then the supervisors length. Regarding the experience, the workers’ score increased with an increase in the years of their experience length. It is assumed that a vast experience has developed their empirical knowledge, which is eventually shown as their risk prediction ability. In the case of the experienced supervisors, it cannot be simply said that their scores increased as their length of experience increased. Because the work load varies depending on the section and the number of foremen, the length of experience does not necessarily correspond to the risk prediction ability. (2)To examine the risk sensitivity and safety awareness, the same risk prediction sheets were shown to students majoring in architecture at Universities A and B. The differences in the responses studied. (3)Four risk prediction sheets, which presented major equipment installation activities, were used to test a cumulative total of 10,032 workers, supervisors (both experienced and inexperienced) and students. Their responses were compared. (4)As a result of the aggregate analysis of the risk prediction sheets, the accuracy rate was found very low among students and newly employed supervisors (i.e. inexperienced supervisors) on most items in all four sheets, compared to the accuracy rate of the supervisors (with experience) and the workers. The experienced supervisors may have accumulated safety knowledge and quick wits to take suitable measures for each occasion, on the basis of safety education and past experience. The accuracy rate of the supervisors exceeded that of the workers only for two items. This is understandable, because the supervisors are required to oversee the work site thoroughly and shoulder many responsible tasks in addition to inspection and installation. The accuracy of the workers was higher than that of the supervisors on many items in most sheets. This can be attributed to their strong sense of safety fostered while they commit themselves to onsite work.