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. Some experiments for a heat supply unit and a heat supply system and dynamic simulations for heat demand have been conducted, such as heat storage and supply of the heat supply unit, and COP evaluation of a new CO2 heat pump system using low-temperature exhaust from the cogeneration system.