Toshihiro Hori

Development of a New Cogeneration System for Local Community

In order for economically viable distributed generation systems for local community to spread, it is essential to develop an efficient and low-cost heat supply system. We propose a new heat supply system presented at the ICOPE-05 Chicago. The key technology for the system is to connect compact heat supply units installed in all the households of the local community, such as a condominium, by a single loop of hot water piping. Phase change material was used for a heat supply unit as heat storage material. However to improve handling ability and to reduce the cost down 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 heat storage material. Furthermore, we constructed a heat supply system for 7 lived-in households with a 5 kW gas engine and a 42 kW boiler as heat sources.

Development of New Heat Supply Unit Using Latent Heat (Dynamic Characteristics of Heat Storage Unit by a Use of Plate Fin Type Heat Exchanger)

A high efficient co-generation system named “Neighboring Communities Co-generation System” is proposed to a multiple dwelling house. The key technology of this system is to connect home and home with one loop of heat transfer line of one-inch diameter, and to level the heat demand by a heat storage unit in each house. This system requires compact heat storage unit of quick response. In this study, a plate fin type brazing heat exchanger was built and tested as a heat storage unit. Sodium acetate trihydrate with a melting point of about 58°C and paraffin wax with a higher value of 74.8°C were used as the phase change material (PCM). As a result, it was shown that the heat transfer in the heat storage unit was dominated by thermal conductivity in PCM. Paraffin wax showed higher responsibility and higher heat output due to its higher melting point and quite lower super cooling in solidification.

Development of Single Loop Heat Supply System for Local Community Cogeneration: Prototype Test of a Heat Supply Unit With Heat Storage and Tap Water Preheating by Heat Pump Unit

In order for economically viable distributed generation systems for local community to spread, it is essential to develop an efficient and low-cost heat supply system. We propose a new heat supply system called DREAMS (Distributed Residential Energy with Advanced Management System). The key technology for the system is to connect compact heat supply units installed in all the households of the local community, such as a condominium, by a single loop of hot water piping. Two methods to decrease the heat supply rate through the single loop are proposed in this paper. The one is an utilization of a compact heat supply unit with heat storage in each house. The momentary heat demand can be covered by the heat storage. The other is a tap water preheating. A new CO2 regenerative heat pump cycle was proposed for the recover of the low temperature heat from the generator. A new heat supply unit with a practical capacity was manufactured, and the heat supply performance was evaluated by some experiments. Furthermore, an advanced energy management system has been under consideration to realize the effective system operation by utilizing IT. In this paper, experimental results on the performance of the new heat supply unit, the new CO2 heat pump system and evaluation of the energy-saving effect of our DREAMS are presented.© 2005 ASME

Development of New Heat Supply Unit Using Latent Heat: Dynamic Characteristics of Heat Storage Unit by a Use of Plate Fin Type Heat Exchanger

A high efficient co-generation system named “Neighboring Communities Co-generation System” is proposed to a multiple dwelling house. The key technology of this system is to connect home and home with one loop of heat transfer line of one-inch diameter, and to level the heat demand by a heat storage unit in each house. This system requires a compact heat storage unit of quick response. In this study, a plate fin type brazing heat exchanger was built and tested as the heat storage unit. Sodium acetate trihydrate with a melting point of about 58 °C and a paraffin wax with a higher value of 74.8 °C were used as the phase change material (PCM). As a result, it was shown that the heat transfer in the heat storage unit was dominated by thermal conductivity in PCM. The paraffin wax showed higher responsibility and higher heat output due to its higher melting point and quite lower super cooling in solidification.Copyright