Conceptual design and development of an automated co-generation system

Abstract

Co-generation or Combined Heat and Power (CHP) is the simultaneous generation of both electricity and heat from the same fuel for useful purposes. The fuel varies greatly and can include coal, biomass, natural gas, nuclear material, the sun or heat stored in the earth. Co-generation (as a vector of energy efficiency) and renewable sources of energy possess their own set of low carbon benefits. Coupling co-generation and renewable sources contribute to a very strong proposition since it leads to the supply of both low-carbon electricity and low-carbon heat. In the case of co-generation plants fuelled by renewable energy sources, the low-carbon benefits of the heat are obvious since they derive from the renewable nature of the fuel. However, this also apply in the case of plants feed by other types of fuel. Such plants produce excess heat alongside electricity. When this heat, which is an unavoidable by-product, is used to satisfy an existing heat demand carbon dioxide (CO2) emissions are reduced overall, through a more efficient use of the fuel. The distributed generation systems produce energy close to the point of use, which typically doubles the efficiency in terms of fuel input‐to‐energy output ratio compared to conventional power generation in central plants. This means that the same amount of energy can be produced with half the amount of fuel, making distributed generation an effective approach to reducing greenhouse gas emissions. According to official government reports, the creation of distributed generation systems will account for at least 5% of gas reduction. In this paper the conceptual design and development of an automated co-generation system to apply in collective residences is presented. After concluding the definition of the demanded specifications and requirements for the co-generation system it is presented and discussed the developed solution with the identification of the main components, including the selection and prototype implementation of the necessary sensors and actuators that integrate the system. It is also shown a systematized approach that consists in using the GEMMA and the SFC formalisms for the structure and specification of all the system behaviour, considering all the stop states and functioning modes of the co-generation system.