Makoto Koganei

Study on Noncondensing Air-Conditioning System Performance When Combining a Desiccant Cooling System with a CO2 Heat Pump

In hot and humid climates, dampness in buildings leads to significant microbial pollution and building damage. In order to alleviate this problem, a desiccant cooling system was suggested as a suitable system to improve indoor air quality (IAQ) based on its superior humidity control. However, such systems have lower energy efficiency, so their combined use with a solar hot water/air supply system or a cogeneration system is common to improve energy efficiency. In this paper, the authors studied the possibilities and methods of combining a desiccant cooling system with a CO2 heat pump to improve overall energy efficiency and provide a steady heat source. The authors also studied the adaptability of the system under a midsummer climate and evaluated the performance of thermal comfort, IAQ, and energy efficiency using the experimental and performance data of the CO2 heat pump.

Study on Outside Air Cooling Systems Used in Data Processing Facilities

Abstract It is currently estimated that with the increasing numbers of IT equipment, the amount of information data used by society will reach 200 times the present volume by 2025. Under such circumstances, there is an urgent requirement for cooling systems in server rooms with high density servers and compatibility with faster and larger servers along with high environmental efficiency. This survey carried out an experiment in which energy performance measurements with variance of outside air taken into the server room in a real size server room were taken. The results show that the cooling load of air conditioners could be approximately 90 percent less than that of the conventional air conditioning system for server rooms and that the overall energy consumption and COP are increased by 18 percent and 24 percent of the maximum respectively, compared to those of the conventional systems under maximum heat load conditions.

A ubiquitous power with DC micro-grid for Sectional Compact Emergency Shelters

This paper proposes a mobile power for the Sectional Compact Emergency Shelter (SCES), which is used under the great disaster. The proposed mobile power consists of the Fuel Cells (FCs), photovoltaic cells (PVs) and lithium-ion rechargeable batteries. This mobile power is constructed in a container car. Therefore, the constructed mobile power is easily moveable and constructible with the SCESs. The authors have named it “a ubiquitous power.” The FCs in the ubiquitous power can supply electrical power and waste-heated water. The waste-heated water can be used to the SCESs for a floor heating in winter. The lithium-ion rechargeable batteries level the difference between generated power and consumed power in the SCESs. The number of the SCESs, which proposed one ubiquitous power can supply power continuously, is decided considering both the depth of discharge (DOD) of the batteries and the thermal energy of the waste-heated water from the FCs. It is shown that proposed one ubiquitous power can supply twenty SCESs in winter in Japan.