Development of Instantaneous Hot Water Dispenser Based on Water Source Heat Pump

Natural energy use is important to reduce the energy consumption of buildings. However, further reducing energy consumption with traditional systems is difficult. Therefore, we proposed a MMHP （multi-source and multi-use heat pump） to achieve higher efficiency than traditional systems. The MMHP system connects multiple heat sources such as solar heat, the ground, and air and multiple heat uses such as cooling, heating, and a hot water dispenser with a water loop. Each type of heat use side can utilize heat efficiently. However, there is a distinct lack of highly efficient hot water dispensers available. Therefore, we developed the IHWD WS （instantaneous hot water dispenser based on a water source） heat pump. In this study, we developed a prototype of the IHWD WS heat pump. The coefficient of performance of the IHWD WS heat pump was 5.2-8.5 throughout a year. When it is improved, COP （coefficient of performance） is expected to be 9.3-9.9.     

Optimum design for smoke-control system in buildings considering robustness using CFD and Genetic Algorithms

In fire-prevention designs for buildings, the major concerns are ensuring safe evacuation in the event of a fire and preventing the fire from spreading. Fire inevitably involves many uncertainties, such as the site of the fire source, whether or not a window is open, erroneous operation of prevention systems, and so on, which increases the risk leading to a large disaster. It is very important to consider these uncertainties to design a safe fire-prevention system. In this research, the optimum design method considering the robustness of smoke-control systems in buildings is developed using an approach that couples Computational Fluid Dynamics (CFD) with Genetic Algorithms (GA). The general optimum design and robust design for a vestibule pressurization smoke-control system in an office are conducted. As a result, although the airflow rate through the doorway of the vestibule, intended to ensure that smoke does not escape into the vestibule during evacuation, is a little lower than the general optimum design, the safety performance of the system is more stable in the robust case. The optimum design method proved to be useful in terms of the fire-prevention system design. The approach will be conducted for other urban safety design.     

HEAT TRANSFER IN A CONDUCTIVE-HEATING AGITATED DRYER

Abstract

The heat transfers between the heating plane and the granular materials in both the “Stationary heating-plane type” and the “Moving heating-plane type” of the conductive-heating agitated dryers were discussed mainly from the view point of the scale-up of the dryer. Under the condition of complete mixing in the bed of bulk materials, the heat transfer models proposed for both the two types of dryers can predict the heat transfer coefficients in any sizes of the dryers. However, the complete mixing is not usually accomplished in the large scale of dryer. Hence, an “Incomplete mixing model” was proposed to estimate the effect of the incompleteness of mixing on the heat transfer coefficient. In this model, the incompleteness of mixing can be apparently taken into consideration only by increasing the contact time.     

Polyelectrolyte complex prepared from carboxymethylated and aminoacetalized derivatives of poly(vinyl alcohol)

Some physical and chemical properties of an ionic complex made from the weak polyelectrolytes carboxymethylated poly(vinyl alcohol) (PA) and aminoacetalized poly(vinyl alcohol) (PC) are investigated in comparison with those of another ionic complex made from the strong polyelectrolytes sulfated poly(vinyl alcohol) (PSA) and poly(vinyl alcohol) acetalized with diethoxyethyltrimethylammonium (PTC). It was found that when the complex PC–PA was heated at high temperatures, covalent amide bonding took place, whereas no significant change occurred in the case of the PTC–PSA complex. As a result of these structural changes, the degree of swelling of the PC–PA complex in water was markedly decreased, but that of the PTC–PSA complex was not changed by the treatment. The PC–PA complex was insoluble in water and in 1N HCI and 1N NaOH aqueous solutions even if not heat treated, but the PTC–PSA complex was soluble in such acidic and basic aqueous solutions but not in water if heat treated. The PC–PA and PTC–PSA films exhibited good mechanical properties.