Investigation of a topping/bottoming ORC Based CHP Configuration Integrating a New Evaporator Concept for Residential Applicationsorc2019 Tracking Number 88 Presentation: Session: Poster session and Ouzo tasting in room Kallirhoe Room: --- Session start: 17:20 Mon 09 Sep 2019 João S Pereira joao.pereira@dem.uc.pt Affifliation: University of Coimbra José B Ribeiro jose.baranda@dem.uc.pt Affifliation: University of Coimbra Ricardo Mendes ricardo.mendes@dem.uc.pt Affifliation: University of Coimbra Jorge C André jorge.andre@dem.uc.pt Affifliation: University of Coimbra Topics: - System Design and Optimization (Topics), - Heat Exchangers (Topics), - Domestic/multigeneration systems (Topics), - Oral Presentation (Preferred Presentation type), - Poster Presentation (Preferred Presentation type) Abstract: The recommended design principles for the development of evaporators for ORC based micro-CHP systems attempting to retrofit the current combi-boilers are presented and discussed in this paper. From those principles, among which is the need of organic fluid direct vaporization, emerged a hybrid (topping/bottoming) CHP configuration in which the thermal energy is produced stepwise: firstly in the ORC-condenser and then in a post-heater, that is integrated on the ORC-evaporator, directly with the combustion gases. A model of this configuration was developed to determine the fraction of the CHP water heating process performed in the post-heater that maximizes the primary energy savings and ORC net power output for a wide range of CHP operating conditions. When compared to a standard CHP configuration, this solution show benefits for the greater part of those conditions. Besides solving the safety issue posed by the ORC-evaporator requirements and the performance benefits shown, this configuration has an additional positive side effect: the decrease of the combustion gases’ temperature before they reach the organic working fluid heat-exchanger section in the ORC-evaporator that leads to a reduction of the risk of the working fluid thermal degradation. |