Weijun Gao

Optimal Sizing for Residential CHP System

Residential CHP systems have been introduced around Japan recently, and expected to diffuse more and more. During the process of boosting the adoption of residential CHP systems, both manufacturers and customers are interested to know the optimal capacity of power generator for the unit, and once the unit has been installed, what dispatch strategy to use in order to minimize a customer’s cost of meeting its electricity and heat demands.

Possibility and potential of clean development mechanisms in China

China has become the worlds second largest greenhouse gas (GHG) emitter behind the United States. It emits approximately three billion tons of CO2 equivalents every year. Its growing economy and large population are making a wealthier, more consumption-oriented country. Energy demand is expected to grow 5–10% per year through 2030. Therefore, a large potential of GHG emission reduction in China can be expected. The clean development mechanism (CDM) put forward in the Kyoto Protocol for reductions of GHGs can support the sustainable development of developing countries and help developed countries to achieve their emission reduction targets at low cost. However, there are still many disagreements to be resolved between developing and developed countries. In this letter, we try to introduce the current development of CDM projects in China and discuss its potential and opportunities in the future decades.

Investigation on the Situation of Combined Heating and Power System in Japan

Abstract In Japan, during the last 20 years, combined heating and power (CHP) system has been developed rapidly. In order to grasp the present condition of introduction and the existing problems of CHP system, the questionnaire survey on CHP system had been carried out at Tokyo. According to the results of investigation, it can be summarized as follows: 1) CHP system had been used widely in various sectors. The generating electricity capacity ranged several ten to several thousands kilowatt. 2) The percentage of CHP total capacity to the electricity demand peak was low and the average value for all users investigated was only 25%. 3) Gas turbine and gas engine achieved 60%-80% overall energy utilization efficiency with 20%-34.5% generating electricity efficiency and 19.5%-50% exhaust heat utilization efficiency. 4) Education buildings had the maximum average generating electricity efficiency with 30.6%, followed by hospital buildings with 29.6%, amusement facilities with 29.5%, office buildings with 28% and compound buildings with 25%. Hospitals attained the maximum average exhaust heat utilization efficiency with 46.1%, followed by offices with 41.3% and compound buildings 39.8%. 5) Various users had different motivation of selecting CHP system. Both office and compound buildings selected economy as the most important reason introducing CHP system; while hospital and education users concerned more saving energy. Hospital and office users were satisfied with the CHP system introduced; while compound building users were not satisfied very much with the CHP system

The Effects of Fuel Price and System Efficiency on Cost and Energy Savings in a Distributed Energy System

Abstract This paper presents a simple model of a distributed energy system, which was introduced in the Kitakyushu Science and Research Park, in order to evaluate the energy saving and operating characteristics of the distributed generation system. We analyzed the effects of fuel price and equipment efficiency on the operating time, running cost and energy saving. The increase of electricity price and decrease of gas price will enhance the attractiveness of the distributed energy resource. According to the load function of the system, energy-saving and environmental improvement will have a maximum value at its optimal operating time. Compared with heat recovery efficiency, power generation efficiency has more influence on energy saving and CO2 reduction when total efficiency of the system is assured.

Numerical Analysis about Urban Climate Change by Urbanization in Shanghai

abstract After the industrial revolution, megalopolis beyond the population of 10,000,000 appears one after another, and makes big impact to the earth environment. The urbanization in Asian developing countries is tremendous. Especially the rapid urban sprawl and the change of land use are bringing urban climate changing such as heat island phenomenon in Shanghai, China in recent years. To evaluate heat island phenomenon in Shanghai by urbanization, this study constructed a land use database using land use map of Shanghai. Using a numerical analysis method, the influence on urban climate with the urban sprawl and the change of land use of Shanghai was evaluated from 1845 to 1995. As a result, analyzed the influence on the urban climate affect by the urbanization of 25km x 19km range, the maximum temperature and average temperature rose by about 1.7ºC because of the rapid sprawl of urban area and the changes of land use for this 150 years in Shanghai.

Energy Consumption and its Impact on Environment in Shanghai, China

Abstract In this paper, we tried to investigate the situation of the energy consumption increase and its influence on the environment as a result of the economic development of Shanghai. The increase of energy consumption associated with mass production and mass consumption in order to improve the quality of human life is inevitable. But we have to exert the power to change the energy structure and improve the exhaust processing in order to conserve the environment. Observing the characteristics of energy consumption in Shanghai, the air pollution problem is caused mainly by the burning of coal and petroleum. We have found that the density of SOx and TSP in the atmosphere is decreasing year by year because the Shanghai government is trying to adjust the industrial structure and energy consumption. The density of Nox, however, is increasing gradually because of an increase in automobile ownership.

Evaluation on Introducing a DHC System with Co-Generation System in the City Center of Shenzhen

In order to keep sustainable development in Asia in the 21st century, we have to solve the global environmental problems because of the huge energy consumption with rapid economical growth. One solution is to use new energy and environmental system. For example, co-generation system is one available approach. In this article, we make a District Heating and Cooling (DHC) system together with co-generation system (CGS) to meet the increasing energy demand in the quickly developed area-City Center in Shenzhen city, and evaluate the whole system from the viewpoint of energy saving and environmental protection.

Study on the Installation of Thermal Storage System in Residential Houses

Abstract In recent years, residential houses have become more airtight and better insulated, and some, along with the IT revolution have been equipped with SOHO applications. This leads to a decrease in the heating load, while increasing electricity consumption in the daytime. On the other hand, electricity demand has increased in the summer, while the load rate of equipment in electricity plants has been decreased. Here a new thermal storage air conditioning system, using direct heat exchange, is proposed for a residential house, while its possibility and availability have been studied according to the prediction of energy consumption, which demonstrates the effectiveness of the thermal storage system for residential houses.

Investigation of City Living Environment and Energy Consumption in Yangtze Delta Area

Yangtze Delta Area is most developed area in China, the center of which is Shanghai, a largest economical city and largest harbor for industry and trade. Besides Shanghai, this area has many cities with a high economical power and highly developed urbanization. The GDP is about 195 billion USD about 20% of the all cities in China. GDP for person is twice than average value of all the cities. The development of economy and living condition in this area will give a significant impact on other cities in China. In this paper, we have an investigation on situation relating with living environment and energy consumption in cities of Yangtze Delta Area by using China statistical data.

Analysis on the Influence of Atmospheric Pollution Caused by Increasing Automobile in Shanghai

This article mainly studies the influence between the increase of automobiles and air pollution in Shanghai, and analyzes the relationship between the increase of automobiles and the national economy development and tries to find out a solution to mitigate the influence of the increase of automobiles on air pollution. The increase of automobiles is linear to the increase of the GDP, and it does not have direct relation with the increase of population. The pollution caused by automobiles is getting more and more serious in the urban area in Shanghai, and automobiles have become the main factor causing the urban air pollution. There are some important measures to reduce the pollution of the environment such as to meliorate traffic, limit the increase of automobiles, develop a public traffic and increase green area.