Masaru Nishida

Wind tunnel tests of wind pressure on regularly aligned buildings

Abstract Model experiments are carried out in order to make the characteristics of wind pressure on groups of buildings clear. The wind pressure is thought to be a natural ventilation force and the model buildings are assumed to be apartment buildings. The approaching flow of the wind tunnel tests simulates the wind over a built-up area. The main parameter of the layout of buildings is the building volume ratio. A staggered grid layout is compared with a normal grid layout. The effect of the wind direction is also examined. The results of the experiments are presented as the wind pressure coefficient difference between windward and leeward. The relations between the average wind pressure coefficient in a model and various layouts of buildings are mainly discussed. The distributions of the wind pressure coefficient in model buildings are also presented in this paper.

Current Status and Future Scenarios of Residential Building Energy Consumption in China

E RNEST O RLANDO L AWRENCE B ERKELEY N ATIONAL L ABORATORY Current Status and Future Scenarios of Residential Building Energy Consumption in China Nan Zhou Environmental Energy Technologies Division Masaru Nishida Department of Architecture Kyushu Sangyo University Weijun Gao Department of Environment Space Design The University of Kitakyushu December 2008 This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Cooling effects of a river and sea breeze on the thermal environment in a built-up area

Abstract Two kinds of field observation are carried out to examine the cooling effects of a river and a sea breeze on the thermal environment in a built-up area in summer. One is the measurements along a river and an avenue which go in the direction of the sea-land breeze. The other is the measurements along a street nearly perpendicular to the river. The wind speed above the river is larger than that above the street when the sea breeze blows, while the air temperature above the river is clearly lower than that above the avenue. The air temperature difference between them falls less downstream of the sea breeze. The air temperature in the space between buildings is the highest in the street and that at the cross point is the next; the wind direction is close to that of the sea breeze. Even if the paths are rather narrow, the ventilation effect by the sea breeze is clearly recognized.

A comparison of field surveys on the thermal environment in urban areas surroundings a large pond: when filled and when drained

Abstract This paper describes the thermal effect of a pond with an area of 127 000 m2 on the surrounding built-up area. Two surveys were conducted and compared, when water filled the pond and after the pond was drained. Moreover, two similar surveys were carried out in the extended area. In the water-filled case, the air temperature distribution demonstrated that a clear cool island was caused by the pond. In the afternoon, it was most prominent with a temperature differential of about three degrees between the center of the pond and the far outside streets, and it extended about a few hundred meters leewards. In the water-drained case, a cool island, caused by the wet bed including water pools left in the leeward half of the pond due to incomplete drainage, diminished with half the differential.

Observations of heat flux in an urban area with a large pond by kytoons

Abstract There are few studies on the thermal environment in urban areas, considering the convective heat flux by natural wind and covering materials on the ground surface. In this paper, the heat flux is calculated from the profiles of the wind speed and the air temperature, which are simultaneously observed by kytoons at three points in an urban area with a large pond, to examine the difference between the built-up area and the water surface, and to make clear the relation between the convective heat transfer and the wind speed.

Evaluation of the Energy and Environmental Performance by Introducing a District Energy System

Abstract In Kitakyushu Science and Research Park, a new district energy system has been introduced. In this study, we chose this system as a case study and have carried out an analysis on the efficiency of the power generation and heat release utilization of the fuel cell and gas engine in summer by using recorded data. The results can be summarized as follows; 1) Although the power generation efficiencies of the gas engine and fuel cell are slightly lower than the standard designated value, they are almost constant throughout the period of study. 2) The collected heat energy is lower than the designated value. The heat release utilization, which is used for cooling and hot water, is lower than expected. Considering the efficient use of energy for such systems, it is important to have a good use of heat release when we introduce a district energy system. 3) The discarded heat energy of the system is very big in this investigation when evaluating the system as a whole. It is fundamental to the future of energy conservation to use primary energy more efficiently.

Study on the Thermal Environment of the YaoDong Dwelling in the Loess Plateau of China

Abstract YaoDong dwellings are distributed widely throughout the loess plateau in the north of China, and have many positive characteristics, such as good use of land, low cost, low impact on the environ-ment, and a comfortable thermal environment. The aim of this study is to ascertain to what extent the indoor climate of YaoDong is a natural one regarding building design as a sustainable architecture. The authors carried out a survey in Zaoyuan village of Yan’an city in August 1999. They collected basic data regarding the natural conditions of the site, climate condition of the Yan’an area, and the thermal environment of YaoDong dwellings. The authors found that YaoDong had excellent charac-teristics regarding the thermal environment in the summer.

The potential for distributed generation in Japanese prototype buildings: A DER-CAM analysis of policy, tariff design, building energy use, and technology development (English Version)

The August 2003 blackout of the northeastern U.S. and CANADA caused great economic losses and inconvenience to New York City and other affected areas. The blackout was a warning to the rest of the world that the ability of conventional power systems to meet growing electricity demand is questionable. Failure of large power systems can lead to serious emergencies. Introduction of on-site generation, renewable energy such as solar and wind power and the effective utilization of exhaust heat is needed, to meet the growing energy demands of the residential and commercial sectors. Additional benefit can be achieved by integrating these distributed technologies into distributed energy resource (DER) systems. This work demonstrates a method for choosing and designing economically optimal DER systems. An additional purpose of this research is to establish a database of energy tariffs, DER technology cost and performance characteristics, and building energy consumption for Japan. This research builds on prior DER studies at the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) and with their associates in the Consortium for Electric Reliability Technology Solutions (CERTS) and operation, including the development of the microgrid concept, and the DER selection optimization program, the Distributed Energy Resources Customer Adoption Model (DER-CAM). DER-CAM is a tool designed to find the optimal combination of installed equipment and an idealized operating schedule to minimize a sites energy bills, given performance and cost data on available DER technologies, utility tariffs, and site electrical and thermal loads over a test period, usually an historic year. Since hourly electric and thermal energy data are rarely available, they are typically developed by building simulation for each of six end use loads used to model the building: electric-only loads, space heating, space cooling, refrigeration, water heating, and natural-gas-only loads. DER-CAM provides a global optimization, albeit idealized, that shows how the necessary useful energy loads can be provided for at minimum cost by selection and operation of on-site generation, heat recovery, cooling, and efficiency improvements. This study examines five prototype commercial buildings and uses DER-CAM to select the economically optimal DER system for each. The five building types are office, hospital, hotel, retail, and sports facility. Each building type was considered for both 5,000 and 10,000 square meter floor sizes. The energy consumption of these building types is based on building energy simulation and published literature. Based on the optimization results, energy conservation and the emissions reduction were also evaluated. Furthermore, a comparison study between Japan and the U.S. has been conducted covering the policy, technology and the utility tariffs effects on DER systems installations. This study begins with an examination of existing DER research. Building energy loads were then generated through simulation (DOE-2) and scaled to match available load data in the literature. Energy tariffs in Japan and the U.S. were then compared: electricity prices did not differ significantly, while commercial gas prices in Japan are much higher than in the U.S. For smaller DER systems, the installation costs in Japan are more than twice those in the U.S., but this difference becomes smaller with larger systems. In Japan, DER systems are eligible for a 1/3 rebate of installation costs, while subsidies in the U.S. vary significantly by region and application. For 10,000 m{sup 2} buildings, significant decreases in fuel consumption, carbon emissions, and energy costs were seen in the economically optimal results. This was most noticeable in the sports facility, followed the hospital and hotel. This research demonstrates that office buildings can benefit from CHP, in contrast to popular opinion. For hospitals and sports facilities, the use of waste heat is particularly effective for water and space heating. For the other building types, waste heat is most effectively used for both heating and cooling. The same examination was done for the 5,000 m{sup 2} buildings. Although CHP installation capacity is smaller and the payback periods are longer, economic, fuel efficiency, and environmental benefits are still seen. While these benefits remain even when subsidies are removed, the increased installation costs lead to lower levels of installation capacity and thus benefit.

INVESTIGATION ON A SUMMER OPERATION EFFECT OF A DISTRICT ENERGY SYSTEM AT KITAKYUSHU SCIENCE RESEARCH CITY(Environmental Engineering)

In Kitakyushu Science and Research Park, a new district energy system has been introduced. In this study, we chose this system as a case study and have carried out an analysis on the efficiency of the power generation and heat release utilization of the fuel cell and gas engine in summer by using the recorded data. The results can be summarized as follows; (1) Although the power generation efficiencies of the gas engine and fuel cell are a little bit lower than the standard designated value, they are almost running at stable condition. (2) The collected heat energy is lower than the designated value. The heat release utilization, which is used for cooling and hot water, is fairly low. Considering the efficient use of energy, it is a key to have a good use of heat release when we introduce a district energy system. (3) The discarded heat energy of the system is very big in this investigation when evaluating the system as a whole. It is fundamental to the future of energy conservation to use primary energy more efficiently.

Study on the Development Process of One Bright Both Sides Dark Type Houses in China

abstract The aim of this paper is to clarify the historical origin of the One Bright Both Sides Dark type of house which has odd-spans frontage and is considered as the typical and traditional unit of the planning composition of Siheyuan houses, and presents a new interpretation of the connection with the typical One Hall Two Insides type in Han dynasty. Further more, the authors attempt to clarify the appearance and development of One Bright Both Sides Dark type houses of China.