Dynamic simulation of new central hot water supply system for residential building

Abstract

In order for economically viable distributed generation systems to spread to residential buildings, it is essential to develop an efficient and low-cost hot water supply system. A new hot water supply system had been proposed for this purpose. The key technology for the system is to connect compact heat storage units installed in each household by a single loop of hot water piping. A prototype plastic tank for heat storage was made and tested in heat storage and heat release operation. Since the cross section area of the tank is small, thermal stratification could be kept in heat release process. On the other hand, in heat storage process, water in the tank was perfectly mixed by incoming hot water flow from the bottom of the tank. Dynamic simulation model of the system for 50 households was constructed on a process simulator using a heat storage tank model, and heat supplying performance was evaluated from the calculated results for heat demand patterns obtained by a field research.