The purpose of this study is to develop the compact auxiliary water heater using tubular flame for home CHP (combined heat and power). The tubular-flame water-heater consists of the tubular flame burner, the coiled tube heat exchanger and the inserted tube installed at the center of the coiled tube as an additional heat exchanger. The tubular flame is formed in a rotating flow field by injecting the air-fuel mixture tangentially into the cylindrical chamber. The swirling flow of the combustion gas flows through the gap between the coiled tube and inserted tube. The high heat transfer performance can be achieved on these heat exchangers without the expanded heat transfer surface due to the swirling flow. Thus, the compact water heater can be constructed by using the tubular flame burner. At the first stage of the development, the maximum thermal efficiency achieves 81 % at the combustion rate of 15 kW. The heat transfer characteristics on the coiled tube and the inserted tube is investigated under the combustion and non-combustion conditions. Heat transfer coefficient on the coiled tube has about 5.6 times higher than that under the no-swirling flow condition at the same flow rate. Nusselt number on the coiled tube heat exchanger and the inserted tube can be estimated by Dhir's correlation equation for the swirling flow, which was provided as a function of the ratio between tangential momentum and axial momentum. The heat transfer characteristics on not only the coiled tube but the inserted tube was dominated by the swirling convection flow.
We have been developing a hybrid LNG vaporization and power generation system which generates approximately −100°C air and natural gas fuel of a steady heating value since March 2004. In this study, three types of intake-cooling process for the Gas Turbine Combined Cycle (GTCC) ranging from several MW to several hundred MW are reviewed. • Cold air is directly introduced as gas turbine intake air and cooled down to approximately 10°C. • Cold air is compressed to about 5 bars and injected into the middle stage of the compressor as an inter-cool medium. • Cold air is compressed, recuperated and injected into the combustor as a power augmentation medium. In this paper, we describe an outline of the test equipment, configurations of the hybrid vaporization and power generation system for the gas turbine and discuss the possibilities based on exergy analysis for the above three cases.
In order for economically viable distributed generation systems for local communities to be widely accepted, it is essential to develop an efficient and low-cost heat supply system. For this purpose, we propose a new heat supply system which we already presented at the ICOPE-05 Chicago. The key technology for the system is to connect compact heat supply units with a heat storage function installed in all the households of the local community, such as condominiums, by a single-loop of hot water pipe. A phase change material was used for the heat supply unit as the heat storage material. However, for easier handling and reducing the cost of the unit, we have developed a new heat supply unit whose heat storage tank is made of plastic. Hot water for space heating is used as the heat storage material. Further we constructed a heat supply system for 7 lived-in households with a 5 kW gas engine and a 42 kW boiler as the heat sources. Some experiments with a heat supply unit and a heat supply system, such as for heat storage and heat supply for peak demand were conducted. Additionally, dynamic simulations of heat demand by 50 households and a COP evaluation of a new CO 2 heat pump system using low-temperature exhaust gas from the gas engine were also conducted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.